Exhibit 1.1

Verona Pharma plc
[·] Ordinary Shares

and

[·] American Depositary Shares
Representing Eight Ordinary Shares
(Nominal value £0.05 Per Share)

UNDERWRITING AGREEMENT

[·], 2017

JEFFERIES LLC
STIFEL, NICOLAUS & COMPANY, INCORPORATED
As Representatives of the several Underwriters

c/o Jefferies LLC
520 Madison Avenue
New York, New York 10022

c/o Stifel, Nicolaus & Company, Incorporated

787 Seventh Avenue, 11th Floor

New York, New York 10019

Ladies and Gentlemen:

Introductory. Verona Pharma plc, a public limited company incorporated under the laws of England and Wales with registered number 5375156 (the “Company”), proposes to issue and sell to the several underwriters named in Schedule A (the “Underwriters”) an aggregate of [·] ordinary shares, nominal value £0.05 per share (the “Ordinary Shares”), of the Company (the “Firm Shares”) and [·] American Depositary Shares (“ADSs”), each representing eight Ordinary Shares (the “Firm ADSs”). The Firm Shares and the Firm ADSs to be sold by the Company are collectively called the “Firm Securities.” In addition, the Company has granted to the Underwriters an option to purchase up to an additional [·] Ordinary Shares (the “Optional Shares”) and up to an additional [·] ADSs (the “Optional ADSs”) as provided in Section 2. The additional Optional Shares and the Optional ADSs to be sold by the Company pursuant to such option are collectively called the “Optional Securities.” The Firm Securities and, if and to the extent such option is exercised, the Optional Securities are collectively called the “Offered Securities.” Unless context otherwise requires, each reference to the Firm Securities, the Optional Securities and the Offered Securities herein also includes the Ordinary Shares represented by the ADSs. Jefferies LLC (“Jefferies”) and Stifel, Nicolaus & Company, Incorporated (“Stifel”) have agreed to act as representatives of the several Underwriters (in such capacity, the “Representatives”) in connection with the offering and sale of the Offered Securities.

The ADSs will be evidenced by American Depositary Receipts (the “ADRs”) to be issued pursuant to a deposit agreement dated as of [·], 2017 (the “Deposit Agreement”), among the Company, Citibank, N.A., as depositary (the “Depositary”), and the holders from time to time of the ADRs evidencing the ADSs issued thereunder.

The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) a registration statement on Form F-1, File No. 333-217124 with respect to the Offered Securities, which contains a form of prospectus to be used in connection with the public offering and sale of the Offered Securities in the form of ADSs in the United States. Such registration statement, as

amended, including the financial statements, exhibits and schedules thereto, in the form in which it became effective under the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder (collectively, the “Securities Act”), including any information deemed to be a part thereof at the time of effectiveness pursuant to Rule 430A under the Securities Act, is called the “Registration Statement.” Any registration statement filed by the Company pursuant to Rule 462(b) under the Securities Act in connection with the offer and sale of the Offered Securities is called the “Rule 462(b) Registration Statement,” and from and after the date and time of filing of any such Rule 462(b) Registration Statement the term “Registration Statement” shall include the Rule 462(b) Registration Statement. The Company has prepared and filed with the Commission a registration statement on Form F-6 (File No. 333-[•]) relating to the ADSs. Such registration statement, as amended, including the financial statements, exhibits and schedules thereto, in the form in which it became effective under the Securities Act is called the “F-6 Registration Statement.” The prospectus, in the form first used by the Underwriters to confirm sales of the Offered Securities or in the form first made available to the Underwriters by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act is called the “Prospectus.” The preliminary prospectus, dated [•], 2017 describing the Offered Securities and the offering thereof is called the “Preliminary Prospectus,” and the Preliminary Prospectus and any other prospectus in preliminary form that describes the Offered Securities and the offering thereof and is used prior to the filing of the Prospectus is called a “preliminary prospectus.” As used herein, “Applicable Time” is [•] p.m. (New York City time) on [•], 2017. As used herein, “free writing prospectus” has the meaning set forth in Rule 405 under the Securities Act, and “Time of Sale Prospectus” means the Preliminary Prospectus, together with the free writing prospectuses, if any, identified in Schedule B hereto and the pricing information identified in Schedule C. As used herein, “Road Show” means a “road show” (as defined in Rule 433 under the Securities Act) relating to the offering of the Offered Securities contemplated hereby that is a “written communication” (as defined in Rule 405 under the Securities Act). As used herein, “Section 5(d) Written Communication” means each written communication (within the meaning of Rule 405 under the Securities Act) that is made in reliance on Section 5(d) of the Securities Act by the Company or any person authorized to act on behalf of the Company to one or more potential investors that are qualified institutional buyers (“QIBs”) and/or institutions that are accredited investors (“IAIs”), as such terms are respectively defined in Rule 144A and Rule 501(a) under the Securities Act, to determine whether such investors might have an interest in the offering of the Offered Securities; “Section 5(d) Oral Communication” means each oral communication, if any, made in reliance on Section 5(d) of the Securities Act by the Company or any person authorized to act on behalf of the Company made to one or more QIBs and/or one or more IAIs to determine whether such investors might have an interest in the offering of the Offered Securities; “Marketing Materials” means any materials or information provided to investors by, or with the approval of, the Company in connection with the marketing of the offering of the Offered Securities, including any roadshow or investor presentations made to investors by the Company (whether in person or electronically); and “Permitted Section 5(d) Communication” means the Section 5(d) Written Communication(s) and Marketing Materials listed on Schedule D attached hereto.

All references in this Agreement to the Registration Statement, the F-6 Registration Statement, any preliminary prospectus (including the Preliminary Prospectus) or the Prospectus, or any amendments or supplements to any of the foregoing, or any free writing prospectus, shall include any copy thereof filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval System (“EDGAR”).

In the event that the Company has only one subsidiary, then all references herein to “subsidiaries” of the Company shall be deemed to refer to such single subsidiary, mutatis mutandis.

The Company hereby confirms its agreements with the Underwriters as follows:

Section 1. Representations and Warranties.

The Company hereby represents, warrants and covenants to each Underwriter, as of the date of this Agreement, as of the First Closing Date (as hereinafter defined) and as of each Option Closing Date (as hereinafter defined), if any, as follows:

(a) Compliance with Registration Requirements. The Registration Statement and the F-6 Registration Statement have each become effective under the Securities Act. The Company has complied, to the Commission’s satisfaction, with all requests of the Commission for additional or supplemental information, if any. No stop order suspending the effectiveness of the Registration Statement or the F-6 Registration Statement is in effect and no proceedings for such purpose have been instituted or are pending or, to the best knowledge of the Company, are contemplated or threatened by the Commission. The Company is a “foreign private issuer” within the meaning of Rule 405 under the Securities Act.

(b) Disclosure. Each preliminary prospectus and the Prospectus when filed complied in all material respects with the Securities Act and, if filed by electronic transmission pursuant to EDGAR, was identical (except as may be permitted by Regulation S-T under the Securities Act) to the copy thereof delivered to the Underwriters for use in connection with the offer and sale of the Offered Securities. Each of the Registration Statement and any post-effective amendment thereto and the F-6 Registration Statement and any post-effective amendment thereto, at the time it became or becomes effective, complied and will comply in all material respects with the Securities Act and did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading. As of the Applicable Time, the Time of Sale Prospectus did not, and at the First Closing Date (as defined in Section 2) and at each applicable Option Closing Date (as defined in Section 2), will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading. The Prospectus, as of its date, did not, and at the First Closing Date and at each applicable Option Closing Date, will not, contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The representations and warranties set forth in the three immediately preceding sentences do not apply to statements in or omissions from the Registration Statement or any post-effective amendment thereto, the F-6 Registration Statement or any post-effective amendment thereto, or the Prospectus or the Time of Sale Prospectus, or any amendments or supplements thereto, made in reliance upon and in conformity with written information relating to any Underwriter furnished to the Company in writing by the Representatives expressly for use therein, it being understood and agreed that the only such information consists of the information described in Section 9(b) below. There are no contracts or other documents required to be described in the Time of Sale Prospectus or the Prospectus or to be filed as an exhibit to the Registration Statement or the F-6 Registration Statement which have not been described or filed as required.

(c) Free Writing Prospectuses; Road Show. As of the determination date referenced in Rule 164(h) under the Securities Act, the Company was not, is not or will not be (as applicable) an “ineligible issuer” in connection with the offering of the Offered Securities pursuant to Rules 164, 405 and 433 under the Securities Act. Each free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or on behalf of or used or referred to by the Company complies or will comply in all material respects with the requirements of Rule 433 under the Securities Act, including timely filing with the Commission or retention where required and legending, and each such free writing prospectus, as of its issue date and at

all subsequent times through the completion of the public offer and sale of the Offered Securities did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement, the Prospectus or any preliminary prospectus that has not been superseded or modified. Except for the free writing prospectuses, if any, identified in Schedule B, and electronic road shows, if any, furnished to you before first use, the Company has not prepared, used or referred to, and will not, without your prior written consent, prepare, use or refer to, any free writing prospectus. Each Road Show, when considered together with the Time of Sale Prospectus, did not, as of the Applicable Time, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(d) Distribution of Offering Material By the Company. Prior to the later of (i) the expiration or termination of the option granted to the several Underwriters in Section 2, (ii) the completion of the Underwriters’ distribution of the Offered Securities and (iii) the expiration of 25 days after the date of the Prospectus, the Company has not distributed and will not distribute any offering material in connection with the offering and sale of the Offered Securities other than the Registration Statement, the F-6 Registration Statement, the Time of Sale Prospectus, the Prospectus or any free writing prospectus reviewed and consented to by the Representatives, the free writing prospectuses, if any, identified on Schedule B hereto and any Permitted Section 5(d) Communications.

(e) The Underwriting Agreement. The Company has the corporate power to enter into this Agreement and this Agreement has been duly authorized, executed and delivered by the Company.

(f) Authorization of the Offered Securities. The Offered Securities in the form of Ordinary Shares have been duly authorized (including pursuant to section 551 of the United Kingdom Companies Act 2006) and, when allotted and issued and delivered against payment therefor pursuant to this Agreement, will be validly allotted and issued, fully paid and not subject to any call for the payment of further capital and will be free of any liens, encumbrances, preemptive rights, rights of first refusal or other similar rights to subscribe for or purchase the Offered Securities in the form of Ordinary Shares and the Ordinary Shares represented by the ADSs, will rank equally in all respects with the existing Ordinary Shares. The Ordinary Shares represented by the ADSs may be freely deposited by the Company with the Depositary or its nominee against issuance of ADRs evidencing such Offered Securities, as contemplated by the Deposit Agreement. The Offered Securities in the form of ADSs have been duly authorized for issuance and sale pursuant to this Agreement (including, in respect of Ordinary Shares represented by the ADSs, pursuant to section 551 of the United Kingdom Companies Act 2006) and, when issued and delivered by the Company against payment therefor pursuant to this Agreement, will be validly issued, fully paid and nonassessable, and the issuance and sale of the Offered Securities in the form of ADSs is not subject to any liens, encumbrances, preemptive rights, rights of first refusal or other similar rights to subscribe for or purchase such Offered Securities (including those provided by section 561 (1) of the United Kingdom Companies Act 2006 in respect of the Ordinary Shares represented by ADSs). Upon the sale and delivery to the Underwriters of the Offered Securities, and payment therefor, the Underwriters will acquire good, marketable and valid title to such Offered Securities, free and clear of all pledges, liens, security interests, charges, claims or encumbrances.

(g) No Applicable Registration or Other Similar Rights. There are no persons with registration or other similar rights to have any equity or debt securities registered for sale under the Registration Statement or the F-6 Registration Statement or included in the offering contemplated by this Agreement.

(h) No Material Adverse Change. Except as otherwise disclosed in the Registration Statement, the Time of Sale Prospectus and the Prospectus, subsequent to the respective dates as of which

information is given in the Registration Statement, the Time of Sale Prospectus and the Prospectus: (i) there has been no material adverse change, or any development that would reasonably be expected to result in a material adverse change, in the condition, financial or otherwise, or in the earnings, business, properties, operations, assets, liabilities or prospects, whether or not arising from transactions in the ordinary course of business, of the Company and its subsidiaries, considered as one entity (any such change being referred to herein as a “Material Adverse Change”); (ii) the Company and its subsidiaries, considered as one entity, have not incurred any material liability or obligation, indirect, direct or contingent, including without limitation any losses or interference with its business from fire, explosion, flood, earthquakes, accident or other calamity, whether or not covered by insurance, or from any strike, labor dispute or court or governmental action, order or decree, that are material, individually or in the aggregate, to the Company and its subsidiaries, considered as one entity, or has entered into any transactions not in the ordinary course of business; and (iii) there has not been any material decrease in the share capital or any material increase in any short-term or long-term indebtedness of the Company or its subsidiaries and there has been no dividend or distribution of any kind declared, paid or made by the Company or, except for dividends paid to the Company or other subsidiaries, by any of the Company’s subsidiaries on any class of share capital, or any repurchase or redemption by the Company or any of its subsidiaries of any class of share capital.

(i) The Deposit Agreement; ADRs. The Deposit Agreement has been duly authorized, executed and delivered by the Company and, assuming due authorization, execution and delivery by the Depositary, constitutes a valid and legally binding obligation of the Company, enforceable in accordance with its terms, except as the enforceability thereof may be limited by bankruptcy, insolvency, reorganization or similar laws relating to or affecting creditors’ rights generally or by general equitable principles. Upon due issuance by the Depositary of the ADRs evidencing the Offered Securities in the form of ADSs against the deposit of the Ordinary Shares in respect thereof in accordance with the provisions of the Deposit Agreement, such ADRs will be duly and validly issued and the persons in whose names the ADRs are registered will be entitled to the rights specified therein and in the Deposit Agreement. The issuance and sale of the Offered Securities in the form of ADSs by the Company and the deposit of the Ordinary Shares with the Depositary and the issuance of the ADRs evidencing such Offered Securities as contemplated by this Agreement and the Deposit Agreement will not trigger any anti-dilution rights of any holder of any Ordinary Shares or ADSs, securities convertible into or exchangeable or exercisable for Ordinary Shares or ADSs or options, warrants or other rights to purchase Ordinary Shares or ADSs or any other securities of the Company with respect to such Ordinary Shares, ADSs, securities, options, warrants or rights, save for any rights of pre-emption under the Companies Act 2006 that have been duly waived or disapplied. The Deposit Agreement and the ADRs conform in all material respects to each description thereof in the Time of Sale Prospectus. Each holder of ADRs issued pursuant to the Deposit Agreement shall be entitled, subject to the Deposit Agreement, to seek enforcement of its rights through the Depositary or its nominee registered as a representative of the holders of the ADRs in a direct suit, action or proceeding against the Company.

(j) Independent Accountants. PricewaterhouseCoopers LLP, which has expressed its opinion with respect to the financial statements (which term as used in this Agreement includes the related notes thereto) filed with the Commission as a part of the Registration Statement, the Time of Sale Prospectus and the Prospectus, is (i) an independent registered public accounting firm as required by the Securities Act and the rules of the Public Company Accounting Oversight Board (“PCAOB”), (ii) in compliance with the applicable requirements relating to the qualification of accountants under Rule 2-01 of Regulation S-X under the Securities Act and (iii) a registered public accounting firm as defined by the PCAOB whose registration has not been suspended or revoked and who has not requested such registration to be withdrawn.

(k) Financial Statements. The financial statements filed with the Commission as a part of the Registration Statement, the Time of Sale Prospectus and the Prospectus present fairly, in all material respects, the consolidated financial position of the Company and its subsidiaries as of the dates indicated and the results of their operations, changes in shareholders’ equity and cash flows for the periods specified. Such financial statements have been prepared in conformity with International Financial Reporting Standards (“IFRS”) as issued by the European Union and the International Accounting Standards Board (the “IASB”) applied on a consistent basis throughout the periods involved, except as may be expressly stated in the related notes thereto. No other financial statements or supporting schedules are required to be included in the Registration Statement, the Time of Sale Prospectus or the Prospectus. The financial data set forth in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus under the captions “Prospectus Summary—Summary Consolidated Financial Data,” “Selected Consolidated Financial Data” and “Capitalization” fairly present, in all material respects, the information set forth therein on a basis consistent with that of the audited financial statements contained in the Registration Statement, the Time of Sale Prospectus and the Prospectus. To the Company’s knowledge, no person who has been suspended or barred from being associated with a registered public accounting firm, or who has failed to comply with any sanction pursuant to Rule 5300 promulgated by the PCAOB, has participated in or otherwise aided the preparation of, or audited, the financial statements, supporting schedules or other financial data filed with the Commission as a part of the Registration Statement, the Time of Sale Prospectus and the Prospectus.

(l) Company’s Accounting System. The Company and each of its subsidiaries make and keep accurate books and records and maintain a system of internal accounting controls designed, and which the Company reasonably believes is sufficient, to provide reasonable assurance that: (i) transactions are executed in accordance with management’s general or specific authorization; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with IFRS as issued by IASB and to maintain accountability for assets; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences. The Company has not received any notice, oral or written, from the Company’s board of directors stating that it is reviewing or investigating, and neither the Company’s independent auditors nor its internal auditors have recommended that the Company’s board of directors review or investigate, (i) adding to, deleting, changing the application of, or changing the Company’s disclosure with respect to, any of the Company’s material accounting policies; or (ii) any matter which could result in a restatement of the Company’s financial statements for any annual or interim period during the current or prior three fiscal years.

(m) Disclosure Controls and Procedures; Deficiencies in or Changes to Internal Control Over Financial Reporting. The Company has established and maintains disclosure controls and procedures (as defined in Rules 13a-15 and 15d-15 under the Exchange Act), which (i) enable the Company to comply with the AIM Rules for Companies; (ii) are designed to ensure that material information relating to the Company, including its consolidated subsidiaries, is made known to the Company’s principal executive officer and its principal financial officer by others within those entities; and (iii) are effective in all material respects to perform the functions for which they were established. Since the end of the Company’s most recent audited fiscal year, there have been no significant deficiencies or material weakness in the Company’s internal control over financial reporting (whether or not remediated) and no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting. The Company is not aware of any change in its internal control over financial reporting that has occurred during its most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

(n) Incorporation and Good Standing of the Company. The Company has been duly incorporated and is validly existing as a public limited company under the laws of England and Wales and has the corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Registration Statement, the Time of Sale Prospectus and the Prospectus and to enter into and perform its obligations under this Agreement. The Company is duly qualified as a foreign corporation to transact business and is in good standing in each other jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure to so qualify or be in good standing would not reasonably be expected, individually or in the aggregate, to have a material adverse effect on the condition (financial or otherwise), earnings, business, properties, operations, assets, liabilities or prospects of the Company and its subsidiaries, taken as a whole (a “Material Adverse Effect”).

(o) Subsidiaries. Each of the Company’s “subsidiaries” (for purposes of this Agreement, as defined in Rule 405 under the Securities Act) has been duly incorporated or organized, as the case may be, and is validly existing as a corporation, partnership or limited liability company, as applicable, in good standing under the laws of the jurisdiction of its incorporation or organization and has the power and authority (corporate or other) to own, lease and operate its properties and to conduct its business as described in the Registration Statement, the Time of Sale Prospectus and the Prospectus. Each of the Company’s subsidiaries is duly qualified as a foreign corporation, partnership or limited liability company, as applicable, to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure to so qualify or be in good standing would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect. All of the issued and outstanding share capital or other equity or ownership interests of each of the Company’s subsidiaries have been duly authorized and validly issued, are fully paid and nonassessable and are owned by the Company, directly or through subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance or adverse claim. None of the outstanding share capital or equity interest in any subsidiary was issued in violation of preemptive or similar rights of any security holder of such subsidiary. The constitutive or organizational documents of each of the subsidiaries comply in all material respects with the requirements of applicable laws of its jurisdiction of incorporation or organization and are in full force and effect. The Company does not own or control, directly or indirectly, any corporation, association or other entity other than the subsidiaries listed in Exhibit 21.1 to the Registration Statement.

(p) Capitalization and Other Share Capital Matters. The authorized, issued and outstanding share capital of the Company is as set forth in the Registration Statement, the Time of Sale Prospectus and the Prospectus under the caption “Capitalization” (other than for subsequent issuances, if any, pursuant to employee benefit plans, or upon the exercise of outstanding options or warrants, in each case described in the Registration Statement, the Time of Sale Prospectus and the Prospectus). The share capital of the Company, including the Offered Securities, conforms in all material respects to each description thereof contained in the Time of Sale Prospectus. All of the issued Ordinary Shares and issued and outstanding ADSs have been duly authorized and validly issued, are fully paid and will not be subject to any call for the payment of further capital and have been issued in compliance with all applicable securities laws. None of the issued Ordinary Shares or issued and outstanding ADSs were issued in violation of any preemptive rights, rights of first refusal or other similar rights to subscribe for or purchase securities of the Company. The form of certificates for the Ordinary Shares conform to the corporate law of the jurisdiction of England and Wales and to any requirements of the Company’s articles of association. There are no authorized or outstanding options, warrants, preemptive rights, rights of first refusal or other rights to purchase, or equity or debt securities convertible into or exchangeable or exercisable for, any share capital of the Company or any of its subsidiaries other than those described in the Registration Statement, the Time of Sale Prospectus and the Prospectus. The descriptions of the Company’s stock option, stock bonus and other stock plans or arrangements, and the options or other

rights granted thereunder, set forth in the Registration Statement, the Time of Sale Prospectus and the Prospectus accurately and fairly presents, in all material respects, the information required to be shown with respect to such plans, arrangements, options and rights. The ADRs evidencing the Offered Securities in the form of ADSs are in due and proper form.

(q) Stock Exchange Listing. The ADSs have been approved for listing on The NASDAQ Global Market (the “NASDAQ”), subject only to official notice of issuance.

(r) Non-Contravention of Existing Instruments; No Further Authorizations or Approvals Required. Neither the Company nor any of its subsidiaries (i) is in violation of its articles of association, partnership agreement or operating agreement or similar constitutional or organizational documents, as applicable, (ii) is in violation of the AIM Rules for Companies and/or, assuming compliance by the Underwriters with the requirements and restrictions described under the captions “Underwriting—Disclaimers About Non-U.S. Jurisdictions—European Economic Area” and “—United Kingdom” in the Registration Statement, the Time of Sale Prospectus and the Prospectus, the UK Financial Conduct Authority’s Prospectus Rules or (iii) is in default (or, with the giving of notice or lapse of time, would be in default) (“Default”) under any indenture, loan, credit agreement, note, lease, license agreement, contract, franchise or other instrument (including, without limitation, any pledge agreement, security agreement, mortgage or other instrument or agreement evidencing, guaranteeing, securing or relating to indebtedness) to which the Company or any of its subsidiaries is a party or by which it or any of them may be bound, or to which any of their respective properties or assets are subject (each, an “Existing Instrument”), except for such Defaults as would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect. The Company’s execution, delivery and performance of this Agreement, consummation of the transactions contemplated hereby, by the Deposit Agreement and by the Registration Statement, the F-6 Registration Statement, the Time of Sale Prospectus and the Prospectus and the issuance and sale of the Offered Securities (including the use of proceeds from the sale of the Offered Securities as described in the Registration Statement, the Time of Sale Prospectus and the Prospectus under the caption “Use of Proceeds”) (i) have been duly authorized by all necessary corporate action and will not result in any violation of the provisions of the articles of association, partnership agreement or operating agreement or similar constitutional or organizational documents, as applicable, of the Company or any subsidiary (ii) will not conflict with or constitute a breach of, or Default or a Debt Repayment Triggering Event (as defined below) under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or any of its subsidiaries pursuant to, or require the consent of any other party to, any Existing Instrument, and (iii) will not result in any violation of any law, administrative regulation or administrative or court decree applicable to the Company or any of its subsidiaries, except in the case of clauses (ii) and (iii), as would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect. No consent, approval, authorization or other order of, or registration or filing with, any court or other governmental or regulatory authority or agency, is required for the Company’s execution, delivery and performance of this Agreement and consummation of the transactions contemplated hereby, by the Deposit Agreement and by the Registration Statement, the F-6 Registration Statement, the Time of Sale Prospectus and the Prospectus, except such as have been obtained or made by the Company and are in full force and effect under the Securities Act and such as may be required under applicable state securities or blue sky laws or the Financial Industry Regulatory Authority, Inc. (“FINRA”), the United Kingdom Companies Act 2006, the UK Financial Services and Markets Act 2000, as amended, EU Regulation (EU 596/2014) on market abuse (the “Market Abuse Regulation”), the NASDAQ, the UK Financial Conduct Authority, the London Stock Exchange plc (“London Stock Exchange”), or AIM, a market operated by London Stock Exchange (“AIM”). As used herein, a “Debt Repayment Triggering Event” means any event or condition which gives, or with the giving of notice or lapse of time would give, the holder of any note, debenture or other evidence of indebtedness (or any person acting on such holder’s behalf) the right to

require the repurchase, redemption or repayment of all or a portion of such indebtedness by the Company or any of its subsidiaries.

(s) Compliance with Laws. The Company and its subsidiaries have been and are in compliance with all applicable laws, rules and regulations, except where failure to be so in compliance would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect.

(t) No Material Actions or Proceedings. There is no action, suit, proceeding, inquiry or investigation brought by or before any governmental entity now pending or, to the knowledge of the Company, threatened, against or affecting the Company or any of its subsidiaries, which would reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect or materially and adversely affect the consummation of the transactions contemplated by this Agreement or the Deposit Agreement or the performance by the Company of its obligations hereunder or thereunder; and the aggregate of all pending legal or governmental proceedings to which the Company or any such subsidiary is a party or of which any of their respective properties or assets is the subject, including ordinary routine litigation incidental to the business, if determined adversely to the Company, would not reasonably be expected to have a Material Adverse Effect. No material labor dispute with the employees of the Company or any of its subsidiaries, or with the employees of any principal supplier, manufacturer, customer or contractor of the Company, exists or, to the knowledge of the Company, is threatened or imminent.

(u) Intellectual Property Rights. Except as disclosed in the Registration Statement, the Time of Sale Prospectus and the Prospectus:

(i) The Company and its subsidiaries own or possess sufficient legal rights to all inventions, patent applications, patents, trademarks, trade names, service names, copyrights, trade secrets and other intellectual property described in the Registration Statement, the Time of Sale Prospectus and the Prospectus as necessary for the conduct of their respective businesses as currently conducted or as currently proposed to be conducted (collectively, “Company Intellectual Property”).

(ii) The product candidates described in the Registration Statement, the Time of Sale Prospectus and the Prospectus as under development by the Company or any subsidiary fall within the scope of claims of one or more patents owned by, or exclusively licensed to, the Company or any subsidiary, except as would not reasonably be expected to have, individually or in the aggregate, a Material Adverse Effect.

(iii) To the Company’s knowledge, no third party has infringed or is infringing any Company Intellectual Property or has otherwise misappropriated or is otherwise misappropriating any Company Intellectual Property.

(iv) To the Company’s knowledge, no Company product or service used, reproduced, modified, distributed, licensed, sublicensed, marketed or sold (or proposed to be used, reproduced, modified, distributed, licensed, sublicensed, marketed or sold) by the Company violates or will violate any license or infringes or will infringe any rights to intellectual property of any other party. The Company has not received any communications alleging that the Company has violated or, by conducting its business, would infringe, misappropriate, dilute, violate or otherwise use without authorization any of intellectual property of any third party. The Company is not aware of any potential infringement of any third party intellectual property, nor are they aware of any facts which would form a reasonable basis for such infringement.

(v) Other than with respect to commercially available software products under standard end-user object code license agreements, the Company is not aware of any outstanding option, license, agreement, claim, encumbrance or shared ownership interest of any kind relating to the Company Intellectual Property, nor is the Company aware of any options, licenses or agreements of any kind with respect to the intellectual property of any other Person other than what is disclosed in the Registration Statement, the Time of Sale Prospectus and the Prospectus.

(vi) To the Company’s knowledge, each item of the Company’s Intellectual Property properly identifies each and every inventor of the claims thereof as determined in accordance with the law of the jurisdiction in which such Company Intellectual Property is issued or pending.

(vii) To the Company’s knowledge, the Company is not in breach of any agreement affecting the Company Intellectual Property, and has not taken any action that would impair or otherwise adversely affects its rights in the Company Intellectual Property, except, in each case, as would not reasonably be expected to have, individually or in the aggregate, a Material Adverse Effect.

(viii) No proceedings are pending or threatened which challenge the validity, enforceability, scope, ownership or use of any Company Intellectual Property. The Company Intellectual Property is not subject to any outstanding order, interference, re-examination, inter partes review, opposition, cancellation proceeding or other post-issuance proceeding. The Company is not aware of any facts which would form a reasonable basis for any such proceedings described in this paragraph (viii).

(ix) To the Company’s knowledge, the Company Intellectual Property is valid and enforceable, and there are no published patent rights, articles, or other prior art references, or any other prior art or material information, that could render invalid or unenforceable or could prevent the issuance of, in whole or in part, any of the Company Intellectual Property or any claim therein. All material prior art of which the Company was aware during the pendency of any application relating to any Company Intellectual Property was properly filed with the patent authorities in the applicable jurisdiction in which such application was pending. For all Company Intellectual Property, the Company and its Representatives have met their duty of candor as required under 37 C.F.R. 1.56 and complied with analogous Law outside the United States requiring disclosure of references.

(x) To the Company’s knowledge, the Company has taken all actions reasonably necessary to protect, and where necessary register, the copyrights, trademarks, patent rights and trade secrets owned by or licensed exclusively to the Company (solely where the Company has the right to take such actions as to in-licensed intellectual property rights).

(xi) Each current and former employee and individual contractor of the Company who is or was involved in the creation or development of any Company Intellectual Property has executed and delivered and, to the Company’s knowledge, is in compliance with an employment or consulting agreement containing nondisclosure, assignment and non-solicitation provisions, except as could not reasonably be expected to have, individually or in the aggregate, a Material Adverse Effect.

(xii) To the Company’s knowledge, none of the Company’s employees or individual contractors is obligated under any agreement, commitment, judgment, decree or order (an “Employee Obligation”) that would or could reasonably be expected to either interfere with the use of his or her best efforts to promote the interests of the Company or conflict with its business as conducted or proposed to be conducted.

(xiii) To the Company’s knowledge, the Company is not using, and it will not be necessary to use, (A) any inventions of any of their past or present employees or individual contractors (or

people currently intended to be hired) made prior to or outside the scope of their employment or consulting agreement by the Company or (B) any confidential information or trade secret of any former employer of any such person.

(v) All Necessary Permits, etc. The Company and its subsidiaries possess such valid and current certificates, authorizations or permits required by state, federal or foreign regulatory agencies or bodies to conduct their respective businesses as currently conducted and as described in the Registration Statement, the Time of Sale Prospectus or the Prospectus (“Permits”), except where failure to possess such Permits would not reasonably be expected, individually or in the aggregate, to result in a Material Adverse Effect. Neither the Company nor any of its subsidiaries is in violation of, or in default under, any of the Permits or has received any notice of proceedings relating to the revocation or modification of, or non-compliance with, any such certificate, authorization or permit, except as would not reasonably be expected, individually or in the aggregate, to result in a Material Adverse Effect.

(w) Title to Properties. The Company and its subsidiaries have good and marketable title to all of the real and personal property and other assets reflected as owned in the financial statements referred to in Section 1(j) above (or elsewhere in the Registration Statement, the Time of Sale Prospectus or the Prospectus), in each case free and clear of any security interests, mortgages, liens, encumbrances, equities, adverse claims and other defects, except such as would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect. The real property, improvements, equipment and personal property held under lease by the Company or any of its subsidiaries are held under valid and enforceable leases, with such exceptions as are not material and do not materially interfere with the use made or proposed to be made of such real property, improvements, equipment or personal property by the Company or such subsidiary.

(x) Tax Law Compliance. The Company and its subsidiaries have filed all necessary federal, state and foreign income and franchise tax returns or have properly requested extensions thereof and have paid all taxes required to be paid by any of them and, if due and payable, any related or similar assessment, fine or penalty levied against any of them except as may be being contested in good faith and by appropriate proceedings or where the failure to file such tax returns or to pay such taxes would not, individually or in the aggregate, result in a Material Adverse Effect. The Company has made adequate charges, accruals and reserves in the applicable financial statements referred to in Section 1(j) above in respect of all federal, state and foreign income and franchise taxes for all periods as to which the tax liability of the Company or any of its subsidiaries has not been finally determined. Except as described in the Registration Statement or the Prospectus, no stamp duty, stamp duty reserve, registration, transfer or other similar taxes or duties (“Transfer Taxes”) are payable in the United Kingdom by or on behalf of the Underwriters in connection with (i) the creation and issuance of the Ordinary Shares by the Company in the manner contemplated by this Agreement and the Deposit Agreement; (ii) the delivery of the Ordinary Shares by the Company to or for the account of the Underwriters in the manner contemplated by this Agreement; (iii) the delivery of the Ordinary Shares by the Company to the Depositary in the manner contemplated by the Deposit Agreement, (iv) the issuance of the Offered ADSs (or the ADRs evidencing the Offered Securities in the form of ADSs) by the Depositary, and the delivery of the Offered ADSs (or the ADRs evidencing the Offered Securities in the form of ADSs) to or for the account of the Underwriters, in each case in the manner contemplated by this Agreement and the Deposit Agreement; (v) the initial sale and delivery by the Underwriters of the Offered Securities (or the ADRs evidencing the Offered Securities in the form of ADSs) to purchasers thereof in the manner contemplated by this Agreement; or (vi) the execution and delivery of this Agreement or the Deposit Agreement.

(y) Insurance. Each of the Company and its subsidiaries are insured by recognized, financially sound and reputable institutions with policies in such amounts and with such deductibles and covering such risks as are generally deemed adequate and customary for their businesses including, but

not limited to, policies covering real and personal property owned or leased by the Company and its subsidiaries against theft, damage, destruction, acts of vandalism and earthquakes and policies covering the Company and its subsidiaries for product liability claims and clinical trial liability claims. The Company has no reason to believe that it or any of its subsidiaries will not be able (i) to renew its existing insurance coverage as and when such policies expire or (ii) to obtain comparable coverage from similar institutions as may be necessary or appropriate to conduct its business as now conducted and at a cost that would not reasonably be expected to have a Material Adverse Effect. Neither the Company nor any of its subsidiaries has been denied any insurance coverage which it has sought or for which it has applied.

(z) Compliance with Environmental Laws. Except as would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect: (i) neither the Company nor any of its subsidiaries is in violation of any federal, state, local or foreign statute, law, rule, regulation, ordinance, code, policy or rule of common law or any judicial or administrative interpretation thereof, including any judicial or administrative order, consent, decree or judgment, relating to pollution or protection of human health, the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata) or wildlife, including, without limitation, laws and regulations relating to the release or threatened release of chemicals, pollutants, contaminants, wastes, toxic substances, hazardous substances, petroleum or petroleum products (collectively, “Hazardous Materials”) or to the manufacture, processing, distribution, use, treatment, storage, disposal, transport or handling of Hazardous Materials (collectively, “Environmental Laws”); (ii) the Company and its subsidiaries have all permits, authorizations and approvals required under any applicable Environmental Laws and are each in compliance with their requirements; (iii) there are no pending or threatened administrative, regulatory or judicial actions, suits, demands, demand letters, claims, liens, notices of noncompliance or violation, investigation or proceedings relating to any Environmental Law against the Company or any of its subsidiaries; and (iv) there are no events or circumstances that might reasonably be expected to form the basis of an order for clean-up or remediation, or an action, suit or proceeding by any private party or governmental body or agency, against or affecting the Company or any of its subsidiaries relating to Hazardous Materials or any Environmental Laws.

(aa) ERISA Compliance. The Company and its subsidiaries and any “employee benefit plan” (as defined under the Employee Retirement Income Security Act of 1974, as amended, and the regulations and published interpretations thereunder (collectively, “ERISA”)) established or maintained by the Company, its subsidiaries or their “ERISA Affiliates” (as defined below) are in compliance in all material respects with ERISA. “ERISA Affiliate” means, with respect to the Company or any of its subsidiaries, any member of any group of organizations described in Sections 414(b), (c), (m) or (o) of the Internal Revenue Code of 1986, as amended, and the regulations and published interpretations thereunder (the “Code”) of which the Company or such subsidiary is a member. No “reportable event” (as defined under ERISA) has occurred or is reasonably expected to occur with respect to any “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates. No “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates, if such “employee benefit plan” were terminated, would have any “amount of unfunded benefit liabilities” (as defined under ERISA). Neither the Company, its subsidiaries nor any of their ERISA Affiliates has incurred or reasonably expects to incur any liability under (i) Title IV of ERISA with respect to termination of, or withdrawal from, any “employee benefit plan” or (ii) Sections 412, 4971, 4975 or 4980B of the Code. Each employee benefit plan established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates that is intended to be qualified under Section 401(a) of the Code is so qualified and nothing has occurred, whether by action or failure to act, which would cause the loss of such qualification.

(bb) Company Not an “Investment Company.” The Company is not, and will not be, either after receipt of payment for the Offered Securities or after the application of the proceeds therefrom as

described under “Use of Proceeds” in the Registration Statement, the Time of Sale Prospectus or the Prospectus, required to register as an “investment company” under the Investment Company Act of 1940, as amended (the “Investment Company Act”).

(cc) No Price Stabilization or Manipulation; Compliance with Regulation M. Neither the Company nor any of its subsidiaries or, to the Company’s knowledge, any of their respective directors, officers or affiliates has taken, directly or indirectly, any action designed to or that would reasonably be expected to cause or result in stabilization or manipulation of the price of the Offered Securities or of any “reference security” (as defined in Rule 100 of Regulation M under the Exchange Act (“Regulation M”)) with respect to the Offered Securities, whether to facilitate the sale or resale of the Offered Securities or otherwise, and has taken no action which would directly or indirectly violate Regulation M.

(dd) Related-Party Transactions. There are no business relationships or related-party transactions involving the Company or any of its subsidiaries or any other person required to be described in the Registration Statement, the Time of Sale Prospectus or the Prospectus that have not been described as required.

(ee) FINRA Matters. The information provided to the Underwriters or to counsel for the Underwriters by the Company and, to the Company’s knowledge, its counsel, its officers and directors and the holders of any securities (debt or equity) or options to acquire any securities of the Company in connection with the offering of the Offered Securities is true, complete, correct in all material respects and compliant with FINRA’s rules and any letters, filings or other supplemental information provided to FINRA pursuant to FINRA Rules or NASD Conduct Rules is true, complete and correct in all material respects.

(ff) Parties to Lock-Up Agreements. The Company has furnished to the Underwriters a letter agreement in the form attached hereto as Exhibit A (the “Lock-up Agreement”) from each of the persons listed on Exhibit B. Such Exhibit B lists under an appropriate caption the directors and officers of the Company. If any additional persons shall become directors or officers of the Company prior to the end of the Company Lock-up Period (as defined below), the Company shall cause each such person, prior to or contemporaneously with their appointment or election as a director or officer of the Company, to execute and deliver to the Representatives a Lock-up Agreement.

(gg) Statistical and Market-Related Data. All statistical, demographic and market-related data included in the Registration Statement, the Time of Sale Prospectus or the Prospectus are based on or derived from sources that the Company believes, after reasonable inquiry, to be reliable and accurate in all material respects. To the extent required, the Company has obtained the written consent to the use of such data from such sources.

(hh) No Unlawful Contributions or Other Payments. Neither the Company nor any of its subsidiaries nor, to the Company’s knowledge, any employee or agent of the Company or any subsidiary, has made any contribution or other payment to any official of, or candidate for, any federal, state or foreign office in violation of any law or of the character required to be disclosed in the Registration Statement, the Time of Sale Prospectus or the Prospectus.

(ii) Anti-Corruption Laws. Neither the Company nor any of its subsidiaries or, to the Company’s knowledge, their respective affiliates nor any director, officer or employee of the Company or any of its subsidiaries or their respective affiliates, any agent, representative or other person associated with or acting on behalf of the Company or any of its subsidiaries or their respective affiliates has, in the course of its actions for, or on behalf of, the Company or any of its subsidiaries (i) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expenses relating to political

activity; (ii) made or taken an act in furtherance of an offer, promise or authorization of any direct or indirect unlawful payment or benefit to any domestic government official, “foreign official” (as defined in the U.S. Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (collectively, the “FCPA”)) or employee, including of any government-owned or controlled entity or of a public international organization, or any person acting in an official capacity for or on behalf of any of the foregoing, or any political party or party official or candidate for political office; (iii) violated or is in violation of any provision of the FCPA or any applicable non-U.S. anti-bribery or anti-corruption laws; or (iv) made, offered, agreed, requested or taken an act in furtherance of any unlawful bribe, rebate, payoff, influence payment, kickback or other unlawful or improper payment or benefit; and the Company and its subsidiaries and, to the Company’s knowledge, its affiliates have conducted their respective businesses in compliance with the applicable anti-bribery and anti-corruption laws and have instituted and maintain and continue to maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance with such laws and with the representation and warranty contained herein.

(jj) Money Laundering Laws. The operations of the Company and its subsidiaries are, and have been conducted at all times, in compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all applicable jurisdictions, the rules and regulations thereunder and any related or similar applicable rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Money Laundering Laws is pending or, to the best knowledge of the Company, threatened.

(kk) OFAC. Neither the Company nor any of its subsidiaries nor, to the knowledge of the Company, after due inquiry, any director, officer, agent, employee, affiliate, representative or person acting on behalf of the Company or any of its subsidiaries is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department (“OFAC”); and the Company will not directly or indirectly use the proceeds of this offering, or lend, contribute or otherwise make available such proceeds to any subsidiary, or any joint venture partner or other person or entity, for the purpose of financing the activities of or business with any person, or in any country or territory, that currently is the subject to any U.S. sanctions administered by OFAC or in any other manner that will result in a violation by any person (including any person participating in the transaction whether as underwriter, advisor, investor or otherwise) of U.S. sanctions administered by OFAC.

(ll) Brokers. Except pursuant to this Agreement, there is no broker, finder or other party that is entitled to receive from the Company any brokerage or finder’s fee or other fee or commission as a result of any transactions contemplated by this Agreement.

(mm) Submission to Jurisdiction. The Company has the power to submit, and pursuant to Section 18 of this Agreement, has legally, validly, effectively and irrevocably submitted, to the personal jurisdiction of each United States federal court and New York state court located in the Borough of Manhattan, in the City of New York, New York, U.S.A. (each, a “New York Court”), and the Company has the power to designate, appoint and authorize, and pursuant to Section 18 of this Agreement, has legally, validly, effectively and irrevocably designated, appointed and authorized an agent for service of process in any action arising out of or relating to this Agreement or the Offered Securities in any New York Court, and service of process effected on such authorized agent will be effective to confer valid personal jurisdiction over the Company as provided in Section 18 hereof.

(nn) Enforceability of Judgement. Any final judgment for a fixed or readily calculable sum of

money rendered by a New York Court having jurisdiction under its own domestic laws and recognized by the English courts as having jurisdiction to give such final judgment in respect of any suit, action or proceeding against the Company based upon this Agreement or the Deposit Agreement and any instruments or agreements entered into for the consummation of the transactions contemplated herein and therein would be declared enforceable against the Company, without re-examination or review of the merits of the cause of action in respect of which the original judgment was given or re-litigation of the matters adjudicated upon, by the courts of England and Wales; provided, however, that the Company may have defenses open to it and enforcement may not be permitted if, among other things, (a) the judgment was obtained by fraud, or in proceedings contrary to natural or substantial justice, or contravenes public policy in England; (b) the judgment is for a sum payable in respect of taxes, or other charges of a like nature or is in respect of a fine or other penalty or otherwise based on a foreign law that an English court considers to relate to a penal, revenue or other public law; (c) the judgment amounts to judgment on a matter previously determined by an English court or conflicts with a judgment on the same matter given by a court other than a New York Court; (d) the judgment is given in proceedings brought in breach of an agreement for the settlement of disputes; (e) the judgment has been arrived at by doubling, trebling or otherwise multiplying a sum assessed as compensation for the loss or damage sustained, or is a judgment that is otherwise specified in section 5 of the Protection of Trading Interests Act 1980, or is a judgment based on measures designated by the Secretary of State under section 1 of that Act; and (f) enforcement proceedings are not commenced within six years of the date of such judgment. The Company is not aware of any reason why the enforcement in England and Wales of such a New York Court judgment would be, as of the date hereof, contrary to public policy of England and Wales.

(oo) No Rights of Immunity. Except as provided by laws or statutes generally applicable to transactions of the type described in this Agreement, neither the Company nor any of its respective properties, assets or revenues has any right of immunity under United Kingdom, New York or United States law, from any legal action, suit or proceeding, from the giving of any relief in any such legal action, suit or proceeding, from set-off or counterclaim, from the jurisdiction of any law of the United Kingdom, New York or United States federal court, from service of process, attachment upon or prior judgment, or attachment in aid of execution of judgment, or from execution of a judgment, or other legal process or proceeding for the giving of any relief or for the enforcement of a judgment, in any such court, with respect to its obligations, liabilities or any other matter under or arising out of or in connection with this Agreement or the Deposit Agreement. To the extent that the Company or any of its respective properties, assets or revenues may have or may hereafter become entitled to any such right of immunity in any such court in which proceedings may at any time be commenced, the Company waives or will waive such right to the extent permitted by law and has consented to such relief and enforcement as provided in Section 18 of this Agreement.

(pp) Forward-Looking Statements. Each financial or operational projection or other “forward-looking statement” (as defined by Section 27A of the Securities Act or Section 21E of the Exchange Act) contained in the Registration Statement, the Time of Sale Prospectus or the Prospectus (i) was so included by the Company in good faith and with reasonable basis after due consideration by the Company of the underlying assumptions, estimates and other applicable facts and circumstances and (ii) is accompanied by meaningful cautionary statements identifying those factors that could cause actual results to differ materially from those in such forward-looking statement. No such statement was made with the knowledge of an executive officer or director of the Company that is was false or misleading.

(qq) Emerging Growth Company Status. From the time of initial confidential submission of the Registration Statement to the Commission (or, if earlier, the first date on which the Company engaged in any Section 5(d) Written Communication or any Section 5(d) Oral Communication) through the date hereof, the Company has been and is an “emerging growth company,” as defined in Section 2(a) of the Securities Act (an “Emerging Growth Company”).

(rr) Communications. The Company (i) has not alone engaged in communications with potential investors in reliance on Section 5(d) of the Securities Act and (ii) has not authorized anyone other than the Representatives to engage in such communications; the Company reconfirms that the Representatives have been authorized to act on its behalf in undertaking Marketing Materials, Section 5(d) Oral Communications and Section 5(d) Written Communications; as of the Applicable Time, each Permitted Section 5(d) Communication, when considered together with the Time of Sale Prospectus, did not, as of the Applicable Time, include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; and each Permitted Section 5(d) Communication, if any, does not, as of the date hereof, conflict with the information contained in the Registration Statement, the Preliminary Prospectus and the Prospectus; and the Company has filed publicly on EDGAR at least 15 calendar days prior to any “road show” (as defined in Rule 433 under the Securities Act), any confidentially submitted registration statement and registration statement amendments relating to the offer and sale of the Offered Securities.

(ss) Clinical Data and Regulatory Compliance. The preclinical tests and clinical trials, and other studies (collectively, “studies”) that are described in, or the results of which are referred to in, the Registration Statement, the Time of Sale Prospectus or the Prospectus were and, if still pending, are being conducted in all material respects in accordance with applicable laws, rules, regulations and policies of the Food and Drug Administration of the U.S. Department of Health and Human Services (the “FDA”) or any committee thereof or of any other U.S. or foreign government or drug or medical device regulatory agency, or health care facility Institutional Review Board; each description of the results of such studies is accurate and complete in all material respects and fairly presents the data derived from such studies, and the Company and its subsidiaries have no knowledge of any other studies the results of which are materially inconsistent with, or otherwise call into question, the results described or referred to in the Registration Statement, the Time of Sale Prospectuses or the Prospectus; for such studies that have been or are being conducted, the Company and its subsidiaries have made all such filings and obtained all such approvals as may be required by foreign government or drug or medical device regulatory agencies, or foreign health care facility Institutional Review Boards; and no investigational new drug application filed by or on behalf of the Company or any of its subsidiaries with the FDA has been terminated or suspended by the FDA, and neither the FDA nor any applicable foreign regulatory agency has commenced, or, to the knowledge of the Company, threatened to initiate, any action to place a clinical hold order on, or otherwise terminate, delay or suspend, any proposed or ongoing studies conducted or proposed to be conducted by or on behalf of the Company or any of its subsidiaries.

(tt) No Rights to Purchase Preferred Stock. The issuance and sale of the Offered Securities by the Company and the deposit of the Ordinary Shares with the Depositary and the issuance of the ADRs evidencing the Offered Securities in the form of ADSs as contemplated by this Agreement and the Deposit Agreement will not cause any holder of any ADSs or Ordinary Shares, securities convertible into or exchangeable or exercisable for ADSs or Ordinary Shares or options, warrants or other rights to purchase ADSs or Ordinary Shares or any other securities of the Company to have any right to acquire any shares of preferred stock of the Company.

(uu) No Contract Terminations. Neither the Company nor any of its subsidiaries has sent or received any communication regarding termination of, or intent not to renew, any of the contracts or agreements referred to or described in any preliminary prospectus, the Prospectus or any free writing prospectus, or referred to or described in, or filed as an exhibit to, the Registration Statement or the F-6 Registration Statement, and no such termination or non-renewal has been threatened by the Company or any of its subsidiaries or, to the Company’s knowledge, any other party to any such contract or agreement, which threat of termination or non-renewal has not been rescinded as of the date hereof.

(vv) Dividend Restrictions. No subsidiary of the Company is prohibited or restricted, directly or indirectly, from paying dividends to the Company, or from making any other distribution with respect to such subsidiary’s equity securities or from repaying to the Company or any other subsidiary of the Company any amounts that may from time to time become due under any loans or advances to such subsidiary from the Company or from transferring any property or assets to the Company or to any other subsidiary.

(ww) Corporate Governance. The directors of the Company have considered the compliance by the Company with the provisions of the UK Corporate Governance Code (2012) and the Company strives, where practicable for a company of its size and nature, to comply with the standards of good practice prescribed by the UK Corporate Governance Code (2012).

(xx) No Public Offering in European Economic Area. The Company has not made and will not make an offer to the public of the Offered Securities in any member state of the European Economic Area.

(yy) Regulatory Compliance. Except as described in the Registration Statement, the Time of Sale Prospectus or the Prospectus, and except as could not, individually or in the aggregate, have or may reasonably be expected to have a Material Adverse Effect, the Company and its subsidiaries are, and at all time since January 1, 2014 have been, in compliance with all applicable Health Care Laws, and have not engaged in activities which are, as applicable, cause for false claims liability, civil penalties, or mandatory or permissive exclusion from Medicare, Medicaid, or any other state health care program or federal health care program. For purposes of this Agreement, “Health Care Laws” means: the federal Food, Drug and Cosmetic Act (21 U.S.C. § 301 et seq.), the federal Anti-kickback Statute (42 U.S.C. § 1320a-7b(b)), the civil False Claims Act (31 U.S.C. §3729 et seq.), the federal False Statements Law (42 U.S.C. § 1320a-7b(a)), the Civil Monetary Penalties Law (42 U.S.C. §1320a-7a), all criminal laws relating to health care fraud and abuse, including, but not limited, to 18 U.S.C. §§ 286 and 287, the exclusions law (42 U.S.C. § 1320a-7), the statutes, regulations and directives of Medicare (Title XVIII of the Social Security Act), Medicaid (Title XIX of the Social Security Act) and all other government funded or sponsored healthcare programs, the Health Insurance Portability and Accountability Act of 1996 (42 U.S.C. § 1320d et seq.), as amended by the Health Information Technology for Economic and Clinical Health Act of 2009 (42 U.S.C. §17921 et seq.), the regulations promulgated pursuant to such laws, and all other comparable local, state, federal, national, and foreign laws relating to the regulation of the Company. The Company is not a party to any corporate integrity agreements, monitoring agreements, consent decrees, settlement orders, or similar agreements with or imposed by any governmental authority regarding any alleged non-compliance with applicable Health Care Laws. In addition, none of the Company or its subsidiaries or, to the Company’s knowledge, any of their respective directors, officers, employees or agents is or has been debarred, suspended or excluded, or has been convicted of any crime or, to the knowledge of the Company or its subsidiaries, engaged in any conduct that would result in a debarment, suspension or exclusion from any federal or state government health care program or human clinical research, or, to the knowledge of the Company, is subject to any inquiry, investigation, proceeding, or other similar action by a governmental authority that could reasonably be expected to result in any such debarment, suspension, or exclusion.

(zz) No Rated Debt or Preferred Securities. There are no debt or preferred securities issued, or guaranteed, by the Company or its subsidiaries that are rated by a “nationally recognized statistical rating organization,” as such term is defined in Section 3(a)(62) of the Exchange Act.

Any certificate signed by any officer of the Company or any of its subsidiaries and delivered to any Underwriter or to counsel for the Underwriters in connection with the offering, or the purchase and

sale, of the Offered Securities shall be deemed a representation and warranty by the Company to each Underwriter as to the matters covered thereby.

The Company has a reasonable basis for making each of the representations set forth in this Section 1. The Company acknowledges that the Underwriters and, for purposes of the opinions to be delivered pursuant to Section 6 hereof, counsel to the Company and counsel to the Underwriters, will rely upon the accuracy and truthfulness of the foregoing representations and hereby consents to such reliance.

Section 2. Purchase, Sale and Delivery of the Offered Securities.

(a) The Firm Securities. Upon the terms herein set forth, the Company agrees to issue and sell to the several Underwriters an aggregate of [·] Firm ADSs and [·] Firm Shares. On the basis of the representations, warranties and agreements herein contained, and upon the terms but subject to the conditions herein set forth, the Underwriters agree, severally and not jointly, to purchase from the Company the respective number of Firm ADSs and Firm Shares set forth opposite their names on Schedule A. The purchase price per Firm ADS and Firm Share to be paid by the several Underwriters to the Company shall be $[·] per Firm ADS and £[·] per Firm Share, respectively.

(b) The First Closing Date. Delivery of certificates for the Firm Securities to be purchased by the Underwriters and payment therefor shall be made at the offices of Cooley LLP, 1114 Avenue of the Americas, New York, New York 10036 (or such other place as may be agreed to by the Company and the Representatives) at 9:00 a.m. New York City time, on [·], 2017, or such other time and date not later than 1:30 p.m. New York City time, on [·], 2017 as the Representatives shall designate by notice to the Company (the time and date of such closing are called the “First Closing Date”). The Company hereby acknowledges that circumstances under which the Representatives may provide notice to postpone the First Closing Date as originally scheduled include, but are not limited to, any determination by the Company or the Representatives to recirculate to the public copies of an amended or supplemented Prospectus or a delay as contemplated by the provisions of Section 11.

(c) The Optional Securities; Option Closing Date. In addition, on the basis of the representations, warranties and agreements herein contained, and upon the terms but subject to the conditions herein set forth, the Company hereby grants an option to the several Underwriters to purchase, severally and not jointly, up to an aggregate of [·] Optional ADSs and [·] Optional Shares from the Company at the purchase price per share to be paid by the Underwriters for the Firm ADSs and Firm Shares, respectively. The option granted hereunder may be exercised at any time and from time to time in whole or in part upon notice by the Representatives to the Company, which notice may be given at any time within 30 days from the date of this Agreement. Such notice shall set forth (i) the aggregate number of Optional ADSs and Optional Shares, in each case, as to which the Underwriters are exercising the option and (ii) the time, date and place at which certificates for the Optional Securities will be delivered (which time and date may be simultaneous with, but not earlier than, the First Closing Date; and in the event that such time and date are simultaneous with the First Closing Date, the term “First Closing Date” shall refer to the time and date of delivery of the Firm Securities and such Optional Securities). Any such time and date of delivery, if subsequent to the First Closing Date, is called an “Option Closing Date,” shall be determined by the Representatives and shall not be earlier than three or later than five full business days after delivery of such notice of exercise. If any Optional Securities are to be purchased, each Underwriter agrees, severally and not jointly, to purchase the number of Optional Securities (subject to such adjustments to eliminate fractional shares as the Representatives may determine) that bears the same proportion to the total number of Optional Securities to be purchased as the number of Firm Securities set forth on Schedule A opposite the name of such Underwriter bears to the total number of

Firm Securities. The Representatives may cancel the option at any time prior to its expiration by giving written notice of such cancellation to the Company.

(d) Offering of the Offered Securities. The Representatives hereby advise the Company that the Underwriters intend to offer for sale (i) to the public in the United States their respective portions of the Firm ADSs and (ii) in a private placement in Europe and other countries outside of the United States and Canada their respective portions of the Firm Shares, in each case, initially on the terms set forth in the Registration Statement, the Time of Sale Prospectus and the Prospectus, as soon after this Agreement has been executed and the Registration Statement has been declared effective as the Representatives, in their sole judgment, have determined is advisable and practicable.

(e) Payment for the Offered Securities.

(i) Payment for the Offered Securities shall be made at the First Closing Date (and, if applicable, at each Option Closing Date) by wire transfer of immediately available funds to the order of the Company.

(ii) It is understood that the Representatives have been authorized, for their own account and the accounts of the several Underwriters, to accept delivery of and receipt for, and make payment of the purchase price for, the Firm Securities and any Optional Securities the Underwriters have agreed to purchase. Each of Jefferies and Stifel, individually and not as the Representatives of the Underwriters, may (but shall not be obligated to) make payment for any Offered Securities to be purchased by any Underwriter whose funds shall not have been received by the Representatives by the First Closing Date or the applicable Option Closing Date, as the case may be, for the account of such Underwriter, but any such payment shall not relieve such Underwriter from any of its obligations under this Agreement.

(f) Delivery of the Offered Securities. The Company shall deliver, or cause to be delivered to the Representatives for the accounts of the several Underwriters, ADRs for the Firm ADSs and the Firm Shares at the First Closing Date, against release of a wire transfer of immediately available funds for the amount of the purchase price therefor. The Company shall also deliver, or cause to be delivered to the Representatives for the accounts of the several Underwriters, ADRs for the Optional ADSs and the Optional Shares the Underwriters have agreed to purchase at the First Closing Date or the applicable Option Closing Date, as the case may be, against the release of a wire transfer of immediately available funds for the amount of the purchase price therefor. The Offered Securities (including ADRs evidencing Offered Securities in the form of ADSs) shall be registered in such names and denominations as the Representatives shall have requested at least two full business days prior to the First Closing Date (or the applicable Option Closing Date, as the case may be) and shall be made available for inspection on the business day preceding the First Closing Date (or the applicable Option Closing Date, as the case may be) at a location in New York City as the Representatives may designate. Time shall be of the essence, and delivery at the time and place specified in this Agreement is a further condition to the obligations of the Underwriters.

Section 3. Additional Covenants.

The Company further covenants and agrees with each Underwriter as follows:

(a) Delivery of Registration Statement, F-6 Registration Statement, Time of Sale Prospectus and Prospectus. The Company shall furnish to you in New York City, without charge, prior to 10:00 a.m. New York City time on the business day next succeeding the date of this Agreement and during the period when a prospectus relating to the Offered Securities is required by the Securities Act to

be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with sales of the Offered Securities, as many copies of the Time of Sale Prospectus, the Prospectus and any supplements and amendments thereto or to the Registration Statement or the F-6 Registration Statement as you may reasonably request.

(b) Representatives’ Review of Proposed Amendments and Supplements. During the period when a prospectus relating to the Offered Securities is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule), the Company (i) will furnish to the Representatives for review, a reasonable period of time prior to the proposed time of filing of any proposed amendment or supplement to the Registration Statement or the F-6 Registration Statement, a copy of each such amendment or supplement and (ii) will not amend or supplement the Registration Statement or the F-6 Registration Statement without the Representatives’ prior written consent, which shall not be unreasonably withheld, conditioned or delayed. Prior to amending or supplementing any preliminary prospectus, the Time of Sale Prospectus or the Prospectus, the Company shall furnish to the Representatives for review, a reasonable amount of time prior to the time of filing or use of the proposed amendment or supplement, a copy of each such proposed amendment or supplement. The Company shall not file or use any such proposed amendment or supplement without the Representatives’ prior written consent, which shall not be unreasonably withheld, conditioned or delayed. The Company shall file with the Commission within the applicable period specified in Rule 424(b) under the Securities Act any prospectus required to be filed pursuant to such Rule.

(c) Free Writing Prospectuses. The Company shall furnish to the Representatives for review, a reasonable amount of time prior to the proposed time of filing or use thereof, a copy of each proposed free writing prospectus or any amendment or supplement thereto prepared by or on behalf of, used by, or referred to by the Company, and the Company shall not file, use or refer to any proposed free writing prospectus or any amendment or supplement thereto without the Representatives’ prior written consent, which will not be unreasonably withheld, conditioned or delayed. The Company shall furnish to each Underwriter, without charge, as many copies of any free writing prospectus prepared by or on behalf of, used by or referred to by the Company as such Underwriter may reasonably request. If at any time when a prospectus is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with sales of the Offered Securities (but in any event if at any time through and including the First Closing Date) there occurred or occurs an event or development as a result of which any free writing prospectus prepared by or on behalf of, used by, or referred to by the Company conflicted or would conflict with the information contained in the Registration Statement or the F-6 Registration Statement or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at such time, not misleading, the Company shall promptly amend or supplement such free writing prospectus to eliminate or correct such conflict so that the statements in such free writing prospectus as so amended or supplemented will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at such time, not misleading, as the case may be; provided that prior to amending or supplementing any such free writing prospectus, the Company shall furnish to the Representatives for review, a reasonable amount of time prior to the proposed time of filing or use thereof, a copy of such proposed amended or supplemented free writing prospectus, and the Company shall not file, use or refer to any such amended or supplemented free writing prospectus without the Representatives’ prior written consent, which will not be unreasonably withheld, conditioned or delayed.

(d) Filing of Underwriter Free Writing Prospectuses. The Company shall not take any action that would result in an Underwriter or the Company being required to file with the Commission

pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of such Underwriter that such Underwriter otherwise would not have been required to file thereunder.

(e) Amendments and Supplements to Time of Sale Prospectus. If the Time of Sale Prospectus is being used to solicit offers to buy the Offered Securities at a time when the Prospectus is not yet available to prospective purchasers, and any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Time of Sale Prospectus so that the Time of Sale Prospectus does not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when delivered to a prospective purchaser, not misleading, or if any event shall occur or condition exist as a result of which the Time of Sale Prospectus conflicts with the information contained in the Registration Statement, or if, in the opinion of counsel for the Underwriters, it is necessary to amend or supplement the Time of Sale Prospectus to comply with applicable law, the Company shall (subject to Section 3(b) and Section 3(c) hereof) promptly prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to any dealer upon request, either amendments or supplements to the Time of Sale Prospectus so that the statements in the Time of Sale Prospectus as so amended or supplemented will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when delivered to a prospective purchaser, not misleading or so that the Time of Sale Prospectus, as amended or supplemented, will no longer conflict with the information contained in the Registration Statement or the F-6 Registration Statement, or so that the Time of Sale Prospectus, as amended or supplemented, will comply with applicable law.

(f) Certain Notifications and Required Actions. After the date of this Agreement and until such time as the Underwriters are no longer required to deliver a Prospectus in order to confirm sales of Offered Securities, the Company shall promptly advise the Representatives in writing of: (i) the receipt of any comments of, or requests for additional or supplemental information from, the Commission; (ii) the time and date of any filing of any post-effective amendment to the Registration Statement or the F-6 Registration Statement or any amendment or supplement to any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus or the Prospectus; (iii) the time and date that any post-effective amendment to the Registration Statement or the F-6 Registration Statement becomes effective; and (iv) the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto or the F-6 Registration Statement or any post-effective amendment thereto or any amendment or supplement to any preliminary prospectus, the Time of Sale Prospectus or the Prospectus or of any order preventing or suspending the use of any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus or the Prospectus, or of any proceedings to remove, suspend or terminate from listing or quotation the Offered Securities from any securities exchange upon which they are listed for trading or included or designated for quotation, or of the threatening or initiation of any proceedings for any of such purposes. If the Commission shall enter any such stop order at any time, the Company will use its best efforts to obtain the lifting of such order as soon as possible. Additionally, the Company agrees that it shall comply with all applicable provisions of Rule 424(b), Rule 433 and Rule 430A under the Securities Act and will use its reasonable efforts to confirm that any filings made by the Company under Rule 424(b) or Rule 433 were received in a timely manner by the Commission.

(g) Amendments and Supplements to the Prospectus and Other Securities Act Matters. If any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Prospectus so that the Prospectus does not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when the Prospectus is delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) to a purchaser, not misleading, or if in the opinion of the Representatives or counsel for the Underwriters it is otherwise necessary to amend or supplement the Prospectus to comply with

applicable law, the Company agrees (subject to Section 3(b) and Section 3(c)) hereof to promptly prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to any dealer upon request, amendments or supplements to the Prospectus so that the statements in the Prospectus as so amended or supplemented will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when the Prospectus is delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) to a purchaser, not misleading or so that the Prospectus, as amended or supplemented, will comply with applicable law. Neither the Representatives’ consent to, nor delivery of, any such amendment or supplement shall constitute a waiver of any of the Company’s obligations under Section 3(b) or Section 3(c).

(h) Blue Sky Compliance. The Company shall cooperate with the Representatives and counsel for the Underwriters to qualify or register the Offered Securities for sale under (or obtain exemptions from the application of) the state securities or blue sky laws or Canadian provincial securities laws (or other foreign laws) of those jurisdictions designated by the Representatives, shall comply with such laws and shall continue such qualifications, registrations and exemptions in effect so long as required for the distribution of the Offered Securities. The Company shall not be required to qualify as a foreign corporation or to take any action that would subject it to general service of process in any such jurisdiction where it is not presently qualified or where it would be subject to taxation as a foreign corporation. The Company will advise the Representatives promptly of the suspension of the qualification or registration of (or any such exemption relating to) the Offered Securities for offering, sale or trading in any jurisdiction or any initiation or threat of any proceeding for any such purpose, and in the event of the issuance of any order suspending such qualification, registration or exemption, the Company shall use its best efforts to obtain the withdrawal thereof as soon as possible.

(i) Use of Proceeds. The Company shall apply the net proceeds from the sale of the Offered Securities sold by it in the manner described under the caption “Use of Proceeds” in the Registration Statement, the Time of Sale Prospectus and the Prospectus.

(j) Earnings Statement. The Company will make generally available to its security holders and to the Representatives as soon as practicable an earnings statement (which need not be audited) covering a period of at least twelve months beginning with the first fiscal quarter of the Company commencing after the date of this Agreement that will satisfy the provisions of Section 11(a) of the Securities Act and the rules and regulations of the Commission thereunder.

(k) Continued Compliance with Securities Laws. The Company will comply with the Securities Act and the Exchange Act so as to permit the completion of the distribution of the Offered Securities as contemplated by this Agreement, the Registration Statement, the F-6 Registration Statement, the Time of Sale Prospectus and the Prospectus. Without limiting the generality of the foregoing, the Company will, during the period when a prospectus relating to the Offered Securities is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule), file on a timely basis with the Commission and the NASDAQ all reports and documents required to be filed under the Exchange Act. Additionally, the Company shall report the use of proceeds from the issuance of the Offered Securities as may be required under Rule 463 under the Securities Act.

(l) Listing. The Company will use its best efforts to list the ADSs on the NASDAQ, subject only to official notice of issuance.

(m) Admission to AIM. The Company will use its best efforts to procure that the Ordinary Shares represented by ADSs and the Offered Securities in the form of Ordinary Shares are admitted to

trading on AIM by 8:00 a.m. (UK time) on the business day immediately following the First Closing Date, including, without limitation, maintaining the admission of the Ordinary Shares to trading on AIM until such Ordinary Shares are so admitted; to make the appropriate announcements through a regulatory information service of the issue of the ADSs and the Shares and the arrangements contemplated by this Agreement in accordance with AIM Rules for Companies (as applicable) published by the London Stock Exchange from time to time; and otherwise to comply with AIM Rules for Companies in relation to the arrangements contemplated by this Agreement.

(n) Agreement Not to Offer or Sell Additional Shares. During the period commencing on and including the date hereof and continuing through and including the 180th day following the date of the Prospectus (such period being referred to herein as the “Lock-up Period”), the Company will not, without the prior written consent of Jefferies and Stifel (which consent may be withheld in their sole discretion), directly or indirectly:(i) sell, offer to sell, contract to sell or lend any ADSs, Ordinary Shares or Related Securities (as defined below); (ii) effect any short sale, or establish or increase any “put equivalent position” (as defined in Rule 16a-1(h) under the Exchange Act) or liquidate or decrease any “call equivalent position” (as defined in Rule 16a-1(b) under the Exchange Act) of any ADSs, Ordinary Shares or Related Securities; (iii) pledge, hypothecate or grant any security interest in any ADSs, Ordinary Shares or Related Securities; (iv) in any other way transfer or dispose of any ADSs, Ordinary Shares or Related Securities; (v) enter into any swap, hedge or similar arrangement or agreement that transfers, in whole or in part, the economic risk of ownership of any ADSs, Ordinary Shares or Related Securities, regardless of whether any such transaction is to be settled in securities, in cash or otherwise; (vi) announce the offering of any ADSs, Ordinary Shares or Related Securities; (vii) file any registration statement under the Securities Act in respect of any ADSs, Ordinary Shares or Related Securities (other than as contemplated by this Agreement with respect to the Offered Securities); or (viii) publicly announce the intention to do any of the foregoing; provided, however, that the Company may (A) effect the transactions contemplated hereby, (B) issue ADSs, Ordinary Shares or options to purchase ADSs or Ordinary Shares, or issue ADSs or Ordinary Shares upon exercise of options, pursuant to any stock option, stock bonus or other stock plan or arrangement described in the Registration Statement, the Time of Sale Prospectus and the Prospectus, provided that the recipients thereof provide to the Representatives a signed lock-up agreement substantially in the form of Exhibit A hereto (the “Lock-Up Agreement”), (C) issue ADSs or Ordinary Shares pursuant to the exercise of options or warrants, in each case, outstanding on the date hereof and described in the Registration Statement, the Time of Sale Prospectus and the Prospectus, (D) file a registration statement on Form S-8 to register ADSs or Ordinary Shares issuable pursuant to the terms of a stock option, stock bonus or other stock plan or arrangement described in the Registration Statement, Time of Sale Prospectus and the Prospectus, (E) issue ADSs or Ordinary Shares in connection with any joint venture, commercial or collaborative relationship or the acquisition or license by the Company of the securities, business, property or other assets of another person or entity or pursuant to any employee benefit plan as assumed by the Company in connection with any such acquisition; provided, however, that in the case of clause (E) (x) such ADSs or Ordinary Shares shall not in the aggregate exceed 5% of the Company’s outstanding share capital immediately following the consummation of the offering of the Offered Securities contemplated by this Agreement and (y) the recipients thereof provide to the Representatives a signed Lock-Up Agreement. For purposes of the foregoing, “Related Securities” shall mean any options or warrants or other rights to acquire ADSs or Ordinary Shares or any securities exchangeable or exercisable for or convertible into ADSs or Ordinary Shares, or to acquire other securities or rights ultimately exchangeable or exercisable for, or convertible into, ADSs or Ordinary Shares.

(o) Future Reports to the Representatives. During the period of five years hereafter, the Company will furnish to the Representatives, c/o Jefferies, at 520 Madison Avenue, New York, New York 10022, Attention: Global Head of Syndicate: (i) as soon as practicable after the end of each fiscal year, copies of the Annual Report of the Company containing the balance sheet of the Company as of the

close of such fiscal year and statements of income, stockholders’ equity and cash flows for the year then ended and the opinion thereon of the Company’s independent public or certified public accountants; (ii) as soon as practicable after the filing thereof, copies of each Annual Report on Form 20-F, Report on Form 6-K or other report filed by the Company with the Commission or any securities exchange; and (iii) as soon as available, copies of any report or communication of the Company furnished or made available generally to holders of its share capital; provided, however, that the requirements of this Section 3(p) shall be satisfied to the extent that such reports, statement, communications, financial statements or other documents are available on EDGAR.

(p) Investment Limitation. The Company shall not invest or otherwise use the proceeds received by the Company from its sale of the Offered Securities in such a manner as would require the Company or any of its subsidiaries to register as an investment company under the Investment Company Act.

(q) No Stabilization or Manipulation; Compliance with Regulation M. The Company will not take, and will ensure that no affiliate of the Company will take, directly or indirectly, any action designed to or that might cause or result in stabilization or manipulation of the price of the Offered Securities or any reference security with respect to the Offered Securities, whether to facilitate the sale or resale of the Offered Securities or otherwise, and the Company will, and shall cause each of its affiliates to, comply with all applicable provisions of Regulation M.

(r) Enforce Lock-Up Agreements. During the Lock-up Period, the Company will enforce all agreements between the Company and any of its security holders that restrict or prohibit, expressly or in operation, the offer, sale or transfer of ADSs, Ordinary Shares or Related Securities or any of the other actions restricted or prohibited under the terms of the form of Lock-up Agreement. .

(s) Company to Provide Interim Financial Statements. Prior to the First Closing Date and each applicable Option Closing Date, the Company will furnish the Underwriters, as soon as practicable after they have been prepared by or are available to the Company, a copy of any unaudited interim financial statements of the Company for any period subsequent to the period covered by the most recent financial statements appearing in the Registration Statement and the Prospectus.

(t) Deposit Agreement. On the First Closing Date and each applicable Option Closing Date, the Company agrees (i) to deposit Ordinary Shares with the Depositary in accordance with the provisions of the Deposit Agreement and will otherwise comply with the Deposit Agreement so that ADRs evidencing the Offered Securities in the form of ADSs will be executed (and, if applicable, countersigned) and issued by the Depositary against receipt of such Ordinary Shares and delivered to the Underwriters at such Closing Date and (ii) to otherwise comply with the terms of the Deposit Agreement, including without limitation, the covenants set forth in the Deposit Agreement.

(u) Tax Indemnity. The Company will indemnify and hold harmless the Underwriters against any Transfer Tax, including any interest and penalties, which are required to be paid on (i) the issuance of the Offered Securities in the form of ADSs by the Depositary, and the sale and delivery of the Offered Securities to or for the account of the Underwriters in the manner contemplated by this Agreement, (ii) the initial sale and delivery by the Underwriters of the Offered Securities to purchasers thereof in the manner contemplated by this Agreement and (iii) on the execution and delivery of this Agreement.

(v) Transfer Agent. The Company agrees to maintain a transfer agent and, if necessary under the jurisdiction of incorporation of the Company, a registrar for the Shares.

(w) Amendments and Supplements to Permitted Section 5(d) Communications. If at any time following the distribution of any Permitted Section 5(d) Communication, during the period when a prospectus relating to the Offered Securities is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule), there occurred or occurs an event or development as a result of which such Permitted Section 5(d) Communication included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing at that subsequent time, not misleading, the Company will promptly notify the Representatives and will promptly amend or supplement, at its own expense, such Permitted Section 5(d) Communication to eliminate or correct such untrue statement or omission.

(x) Emerging Growth Company Status. The Company will promptly notify the Representatives if the Company ceases to be an Emerging Growth Company at any time prior to the later of (i) the time when a prospectus relating to the Offered Securities is not required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) and (ii) the expiration of the Lock-Up Period (as defined herein).

The Representatives, on behalf of the several Underwriters, may, in their sole discretion, waive in writing the performance by the Company of any one or more of the foregoing covenants or extend the time for their performance.

Section 4. Payment of Expenses. The Company agrees to pay all costs, fees and expenses incurred in connection with the performance of its obligations hereunder and in connection with the transactions contemplated hereby, including without limitation (i) all expenses incident to the issuance, sale and delivery of the Offered Securities (including all printing and engraving costs), (ii) all fees and expenses of the registrar and transfer agent of the Ordinary Shares, (iii) all fees and expenses of the Depositary related to the Offered Securities, (iv) all necessary Transfer Taxes in connection with the issuance and delivery of the Offered Securities to the Underwriters in the manner contemplated by this Agreement, (v) all fees and expenses of the Company’s counsel, independent public or certified public accountants and other advisors, (vi) all costs and expenses incurred in connection with the preparation, printing, filing, shipping and distribution of the Registration Statement (including financial statements, exhibits, schedules, consents and certificates of experts), the F-6 Registration Statement, the Time of Sale Prospectus, the Prospectus, each free writing prospectus prepared by or on behalf of, used by, or referred to by the Company, and each preliminary prospectus, each Permitted Section 5(d) Communication, and all amendments and supplements thereto, and this Agreement, (vii) all filing fees, attorneys’ fees and expenses incurred by the Company or the Underwriters in connection with qualifying or registering (or obtaining exemptions from the qualification or registration of) all or any part of the Offered Securities for offer and sale under the state securities or blue sky laws or the provincial securities laws of Canada, and, if requested by the Representatives, preparing and printing a “Blue Sky Survey” or memorandum (such fees and expenses of counsel relating to such qualification or registration not to exceed $5,000) and a “Canadian wrapper”, and any supplements thereto, advising the Underwriters of such qualifications, registrations and exemptions, (viii) the costs, fees and expenses incurred by the Underwriters in connection with determining their compliance with the rules and regulations of FINRA related to the Underwriters’ participation in the offering and distribution of the Offered Securities, including any related filing fees and the legal fees of, and disbursements by, counsel to the Underwriters in an amount not to exceed $35,000, (ix) the costs and expenses of the Company relating to investor presentations on any “road show”, any Permitted Section 5(d) Communication or any Section 5(d) Oral Communication undertaken in connection with the offering of the Offered Securities, including, without limitation, expenses associated with the preparation or dissemination of any electronic road show, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations with the prior approval of the Company, travel

and lodging expenses of the representatives, employees and officers of the Company and any such consultants, and 50% of the cost of any aircraft chartered in connection with the road show (the remaining 50% of the cost of such aircraft to be paid by the Underwriters), and (ix) the fees and expenses associated with listing the Offered Securities in the form of ADSs on the NASDAQ. Except as provided in this Section 4 or in Section 7, Section 9 or Section 10 hereof, the Underwriters shall pay their own expenses, including the fees and disbursements of their counsel and their travel and lodging expenses.

Section 5. Covenant of the Underwriters. Each Underwriter severally and not jointly covenants with the Company not to take any action that would result in the Company being required to file with the Commission pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of such Underwriter that otherwise would not, but for such actions, be required to be filed by the Company under Rule 433(d).

Section 6. Conditions of the Obligations of the Underwriters. The respective obligations of the several Underwriters hereunder to purchase and pay for the Offered Securities as provided herein on the First Closing Date and, with respect to the Optional Securities, each Option Closing Date, shall be subject to the accuracy of the representations and warranties on the part of the Company set forth in Section 1 hereof as of the date hereof and as of the First Closing Date as though then made and, with respect to the Optional Securities, as of each Option Closing Date as though then made, to the timely performance by the Company of its covenants and other obligations hereunder, and to each of the following additional conditions:

(a) Comfort Letter. On the date hereof, the Representatives shall have received from PricewaterhouseCoopers LLP, independent registered public accountants for the Company, a letter dated the date hereof addressed to the Underwriters, in form and substance satisfactory to the Representatives, containing statements and information of the type ordinarily included in accountant’s “comfort letters” to underwriters, delivered according to Statement of Auditing Standards No. 72 (or any successor bulletin), with respect to the audited and unaudited financial statements and certain financial information contained in the Registration Statement, the Time of Sale Prospectus, and each free writing prospectus, if any.

(b) Compliance with Registration Requirements; No Stop Order; No Objection from FINRA.

(i) The Company shall have filed the Prospectus with the Commission (including the information required by Rule 430A under the Securities Act) in the manner and within the time period required by Rule 424(b) under the Securities Act[; or the Company shall have filed a post-effective amendment to the Registration Statement containing the information required by such Rule 430A, and such post-effective amendment shall have become effective].

(ii) No stop order suspending the effectiveness of the Registration Statement or any post-effective amendment to the Registration Statement or the F-6 Registration Statement or any post-effective amendment to the F-6 Registration Statement shall be in effect, and no proceedings for such purpose shall have been instituted or threatened by the Commission.

(iii) FINRA shall have raised no objection to the fairness and reasonableness of the underwriting terms and arrangements.

(c) No Material Adverse Change. For the period from and after the date of this Agreement and through and including the First Closing Date and, with respect to any Optional Securities purchased after the First Closing Date, each Option Closing Date, in the judgment of the Representatives there shall not have occurred any Material Adverse Change.

(d) Opinion of U.S. Counsel for the Company. On each of the First Closing Date and each Option Closing Date the Representatives shall have received the opinion of Latham & Watkins LLP, U.S. counsel for the Company, dated as of such date, in the form previously agreed to by, and reasonably satisfactory to, the Representatives.

(e) Opinion of UK Counsel for the Company. On each of the First Closing Date and each Option Closing Date the Representatives shall have received the opinion of Latham & Watkins (London) LLP, UK counsel for the Company, dated as of such date, in the form previously agreed to by, and reasonably satisfactory to, the Representatives.

(f) Opinion of J A Kemp. On each of the First Closing Date and each Option Closing Date, the Representatives shall have received the opinion of J A Kemp, counsel for the Company with respect to intellectual property matters, dated as of such date, in the form previously agreed to by, and reasonably satisfactory to, the Representatives.

(g) Opinion of Tax Counsel for the Company, On each of the First Closing Date and each Option Closing Date, the Representatives shall have received the opinion of Latham & Watkins LLP, tax counsel for the Company , dated as of such date, in the form previously agreed to by, and reasonably satisfactory to, the Representatives.

(h) Opinion of Counsel for the Depositary. On each of the First Closing Date and each Option Closing Date, the Representatives shall have received the opinion of Patterson Belknap Webb & Tyler LLP, counsel for the Depositary, dated as of such date, in the form previously agreed to by, and reasonably satisfactory to, the Representatives.

(i) Opinion of U.S. Counsel for the Underwriters. On each of the First Closing Date and each Option Closing Date the Representatives shall have received the opinion of Cooley LLP, U.S. counsel for the Underwriters in connection with the offer and sale of the Offered Securities, in form and substance reasonably satisfactory to the Underwriters, dated as of such date.

(j) Opinion of UK Counsel for the Underwriters. On each of the First Closing Date and each Option Closing Date the Representatives shall have received the opinion of White & Case LLP, UK counsel for the Underwriters in connection with the offer and sale of the Offered Securities, in form and substance reasonably satisfactory to the Underwriters, dated as of such date.

(k) Officers’ Certificate. On each of the First Closing Date and each Option Closing Date, the Representatives shall have received a certificate executed by the Chief Executive Officer or President of the Company and the Chief Financial Officer of the Company, dated as of such date, to the effect set forth in Section 6(b)(ii) and further to the effect that:

(i) for the period from and including the date of this Agreement through and including such date, there has not occurred any Material Adverse Change;

(ii) the representations, warranties and covenants of the Company set forth in Section 1 of this Agreement are true and correct with the same force and effect as though expressly made on and as of such date; and

(iii) the Company has complied with all the agreements hereunder and satisfied all the conditions on its part to be performed or satisfied hereunder at or prior to such date.

(l) Bring-down Comfort Letter. On each of the First Closing Date and each Option Closing Date the Representatives shall have received from PricewaterhouseCoopers LLP, independent registered public accountants for the Company, a letter dated such date, in form and substance satisfactory to the Representatives, which letter shall: (i) reaffirm the statements made in the letter furnished by them pursuant to Section 6(a), except that the specified date referred to therein for the carrying out of procedures shall be no more than three business days prior to the First Closing Date or the applicable Option Closing Date, as the case may be; and (ii) cover certain financial information contained in the Prospectus.

(m) Lock-Up Agreements. On or prior to the date hereof, the Company shall have furnished to the Representatives an agreement in the form of Exhibit A hereto from each of the persons listed on Exhibit B hereto, and each such agreement shall be in full force and effect on each of the First Closing Date and each Option Closing Date.

(n) Rule 462(b) Registration Statement. In the event that a Rule 462(b) Registration Statement is filed in connection with the offering contemplated by this Agreement, such Rule 462(b) Registration Statement shall have been filed with the Commission on the date of this Agreement and shall have become effective automatically upon such filing.

(o) Approval of Listing on the NASDAQ. At the First Closing Date, the Offered Securities in the form of ADSs shall have been approved for listing on the NASDAQ, subject only to official notice of issuance.

(p) Approval of Admission to AIM. The Ordinary Shares are admitted to trading on AIM and the Company shall have applied to the London Stock Exchange for the Ordinary Shares represented by the ADSs and the Offered Securities in the form of Ordinary Shares to be admitted to trading on AIM at 8:00 a.m. (UK time) on the business day immediately following the First Closing Date, which application has not been rejected, and such Ordinary Shares have been allotted conditional only on receipt by the Company of funds for the Ordinary Shares represented by the ADSs and the Offered Securities in the form of Ordinary Shares and admission to AIM.

(q) Deposit Agreement. The Company and the Depositary shall have executed and delivered the Deposit Agreement and the Deposit Agreement shall be in full force and effect. The Depositary shall have delivered to the Company certificates satisfactory to the Underwriters evidencing the deposit with the Depositary or its nominee of the Shares being so deposited against issuance of ADRs evidencing the Offered Securities in the form of ADSs to be delivered by the Company at such Closing Date, and the execution, countersignature (if applicable), issuance and delivery of ADRs evidencing such Offered Securities pursuant to the Deposit Agreement.

(r) Chief Financial Officer’s Certificate. On the date of this Agreement and on each of the First Closing Date and each Option Closing Date, as the case may be, the Representatives shall have received from the Chief Financial Officer, a certificate providing “management comfort” in form and substance reasonably satisfactory to the Representatives, dated the respective dates of delivery thereof and addressed to the Underwriters, with respect to certain financial information contained in the Registration Statement, the Time of Sale Prospectus, and each free writing prospectus, if any.

(s) Additional Documents. On or before each of the First Closing Date and each Option Closing Date, the Representatives and counsel for the Underwriters shall have received such information, documents and opinions as they may reasonably request for the purposes of enabling them to pass upon the issuance and sale of the Offered Securities as contemplated herein, or in order to evidence the accuracy of any of the representations and warranties, or the satisfaction of any of the conditions or

agreements, herein contained; and all proceedings taken by the Company in connection with the issuance and sale of the Offered Securities as contemplated herein and in connection with the other transactions contemplated by this Agreement shall be satisfactory in form and substance to the Representatives and counsel for the Underwriters.

If any condition specified in this Section 6 is not satisfied when and as required to be satisfied, this Agreement may be terminated by the Representatives by notice from Jefferies to the Company at any time on or prior to the First Closing Date and, with respect to the Optional Securities, at any time on or prior to the applicable Option Closing Date, which termination shall be without liability on the part of any party to any other party, except that Section 4, Section 7, Section 9 and Section 10 shall at all times be effective and shall survive such termination.

Section 7. Reimbursement of Underwriters’ Expenses. If this Agreement is terminated by the Representatives pursuant to Section 6 or Section 12, or if the sale to the Underwriters of the Offered Securities on the First Closing Date is not consummated because of any refusal, inability or failure on the part of the Company to perform any agreement herein or to comply with any provision hereof, the Company agrees to reimburse the Representatives and the other Underwriters (or such Underwriters as have terminated this Agreement with respect to themselves), severally, upon demand for all out-of-pocket expenses that shall have been reasonably incurred by the Representatives and the Underwriters in connection with the proposed purchase and the offering and sale of the Offered Securities, including, but not limited to, fees and disbursements of counsel, printing expenses, travel expenses, postage, facsimile and telephone charges; provided, however, that in the event any such termination is effected after the First Closing Date but prior to any Option Closing Date with respect to the purchase of any Optional Securities, the Company shall only reimburse the Underwriters for all of their out of pocket expenses, including the reasonable fees and disbursements of counsel for the Underwriters, incurred after the First Closing Date in connection with the proposed purchase of any such Optional Securities. For the avoidance of doubt, it is understood that the Company will not pay or reimburse any costs, fees or expenses incurred by any Underwriter that defaults on its obligations to purchase the Offered Securities.

Section 8. Effectiveness of this Agreement. This Agreement shall become effective upon the execution and delivery hereof by the parties hereto.

Section 9. Indemnification.

(a) Indemnification of the Underwriters. The Company agrees to indemnify and hold harmless each Underwriter, its affiliates, directors, officers, employees and agents, and each person, if any, who controls any Underwriter within the meaning of the Securities Act or the Exchange Act against any loss, claim, damage, liability or expense, as incurred, to which such Underwriter or such affiliate, director, officer, employee, agent or controlling person may become subject, under the Securities Act, the Exchange Act, other federal or state statutory law or regulation, or the laws or regulations of foreign jurisdictions where Offered Securities have been offered or sold or at common law or otherwise (including in settlement of any litigation, if such settlement is effected with the written consent of the Company), insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based upon (A) (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or the F-6 Registration Statement, or any amendment to the Registration Statement or F-6 Registration Statement, or the omission or alleged omission to state therein a material fact required to be stated in the Registration Statement or F-6 Registration Statement or necessary to make the statements in the Registration Statement or F-6 Registration Statement not misleading; or (ii) any untrue statement or alleged untrue statement of a

material fact included in any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has used, referred to or filed, or is required to file, pursuant to Rule 433(d) of the Securities Act, any Marketing Material, any Section 5(d) Written Communication or the Prospectus (or any amendment or supplement to the foregoing), or the omission or alleged omission to state therein a material fact necessary in order to make the statements, in the light of the circumstances under which they were made, not misleading; and to reimburse each Underwriter and each such affiliate, director, officer, employee, agent and controlling person for any and all expenses (including the fees and disbursements of counsel) as such expenses are incurred by such Underwriter or such affiliate, director, officer, employee, agent or controlling person in connection with investigating, defending, settling, compromising or paying any such loss, claim, damage, liability, expense or action; provided, however, that the foregoing indemnity agreement shall not apply to any loss, claim, damage, liability or expense to the extent, but only to the extent, arising out of or based upon any untrue statement or alleged untrue statement or omission or alleged omission made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company by the Representatives in writing expressly for use in the Registration Statement, the F-6 Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any such free writing prospectus, any Marketing Material, any Section 5(d) Written Communication or the Prospectus (or any amendment or supplement thereto), it being understood and agreed that the only such information consists of the information described in Section 9(b) below. The indemnity agreement set forth in this Section 9(a) shall be in addition to any liabilities that the Company may otherwise have.

(b) Indemnification of the Company, its Directors and Officers. Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, each of its directors, each of its officers who signed the Registration Statement and the F-6 Registration Statement, and each person, if any, who controls the Company within the meaning of the Securities Act or the Exchange Act, against any loss, claim, damage, liability or expense, as incurred, to which the Company, or any such director, officer or controlling person may become subject, under the Securities Act, the Exchange Act, or other federal or state statutory law or regulation, or at common law or otherwise (including in settlement of any litigation, if such settlement is effected with the written consent of such Underwriter), insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or the F-6 Registration Statement, or any amendment to the Registration Statement or F-6 Registration Statement, or the omission or alleged omission to state therein a material fact required to be stated in the Registration Statement or F-6 Registration Statement or necessary to make the statements in the Registration Statement or F-6 Registration Statement not misleading or (ii) any untrue statement or alleged untrue statement of a material fact included in any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has used, referred to or filed, or is required to file, pursuant to Rule 433 of the Securities Act, any Section 5(d) Written Communication or the Prospectus (or any such amendment or supplement) or the omission or alleged omission to state therein a material fact necessary in order to make the statements, in the light of the circumstances under which they were made, not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in the Registration Statement, the F-6 Registration Statement, such preliminary prospectus, the Time of Sale Prospectus, such free writing prospectus, such Section 5(d) Written Communication or the Prospectus (or any such amendment or supplement), in reliance upon and in conformity with information relating to such Underwriter furnished to the Company by the Representatives in writing expressly for use therein; and to reimburse the Company, or any such director, officer or controlling person for any and all expenses (including the fees and disbursements of counsel) as such expenses are incurred by the Company, or any such director, officer or controlling person in connection with investigating, defending, settling, compromising or paying any such loss, claim, damage, liability, expense or action. The Company hereby acknowledges that the only information that the Representatives have furnished to the Company expressly

for use in the Registration Statement, the F-6 Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) of the Securities Act, any Section 5(d) Written Communication or the Prospectus (or any amendment or supplement to the foregoing) are the statements set forth in [paragraphs] under the caption “Underwriting” in the Preliminary Prospectus and the Prospectus. The indemnity agreement set forth in this Section 9(b) shall be in addition to any liabilities that each Underwriter may otherwise have.

(c) Notifications and Other Indemnification Procedures. Promptly after receipt by an indemnified party under this Section 9 of notice of the commencement of any action, such indemnified party will, if a claim in respect thereof is to be made against an indemnifying party under this Section 9, notify the indemnifying party in writing of the commencement thereof, but the omission so to notify the indemnifying party will not relieve the indemnifying party from any liability which it may have to any indemnified party to the extent the indemnifying party is not materially prejudiced as a proximate result of such failure and shall not in any event relieve the indemnifying party from any liability that it may have otherwise than on account of this indemnity agreement. In case any such action is brought against any indemnified party and such indemnified party seeks or intends to seek indemnity from an indemnifying party, the indemnifying party will be entitled to participate in, and, to the extent that it shall elect, jointly with all other indemnifying parties similarly notified, by written notice delivered to the indemnified party promptly after receiving the aforesaid notice from such indemnified party, to assume the defense thereof with counsel reasonably satisfactory to such indemnified party; provided, however, that if the defendants in any such action include both the indemnified party and the indemnifying party and the indemnified party shall have reasonably concluded that a conflict may arise between the positions of the indemnifying party and the indemnified party in conducting the defense of any such action or that there may be legal defenses available to it and/or other indemnified parties which are different from or additional to those available to the indemnifying party, the indemnified party or parties shall have the right to select separate counsel to assume such legal defenses and to otherwise participate in the defense of such action on behalf of such indemnified party or parties. Upon receipt of notice from the indemnifying party to such indemnified party of such indemnifying party’s election so to assume the defense of such action and approval by the indemnified party of counsel, the indemnifying party will not be liable to such indemnified party under this Section 9 for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense thereof unless (i) the indemnified party shall have employed separate counsel in accordance with the proviso to the preceding sentence (it being understood, however, that the indemnifying party shall not be liable for the fees and expenses of more than one separate counsel (together with local counsel), representing the indemnified parties who are parties to such action), which counsel (together with any local counsel) for the indemnified parties shall be selected by Jefferies (in the case of counsel for the indemnified parties referred to in Section 9(a) above) or by the Company (in the case of counsel for the indemnified parties referred to in Section 9(b) above)) or (ii) the indemnifying party shall not have employed counsel satisfactory to the indemnified party to represent the indemnified party within a reasonable time after notice of commencement of the action or (iii) the indemnifying party has authorized in writing the employment of counsel for the indemnified party at the expense of the indemnifying party, in each of which cases the fees and expenses of counsel shall be at the expense of the indemnifying party and shall be paid as they are incurred.

(d) Settlements. The indemnifying party under this Section 9 shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party against any loss, claim, damage, liability or expense by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel as contemplated by Section 9(c) hereof, the indemnifying party shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 30 days after receipt by

such indemnifying party of the aforesaid request and (ii) such indemnifying party shall not have reimbursed the indemnified party in accordance with such request prior to the date of such settlement. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement, compromise or consent to the entry of judgment in any pending or threatened action, suit or proceeding in respect of which any indemnified party is or could have been a party and indemnity was or could have been sought hereunder by such indemnified party, unless such settlement, compromise or consent includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such action, suit or proceeding and does not include an admission of fault or culpability or a failure to act by or on behalf of such indemnified party.

Section 10. Contribution. If the indemnification provided for in Section 9 is for any reason held to be unavailable to or otherwise insufficient to hold harmless an indemnified party in respect of any losses, claims, damages, liabilities or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount paid or payable by such indemnified party, as incurred, as a result of any losses, claims, damages, liabilities or expenses referred to therein (i) in such proportion as is appropriate to reflect the relative benefits received by the Company, on the one hand, and the Underwriters, on the other hand, from the offering of the Offered Securities pursuant to this Agreement or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company, on the one hand, and the Underwriters, on the other hand, in connection with the statements or omissions which resulted in such losses, claims, damages, liabilities or expenses, as well as any other relevant equitable considerations. The relative benefits received by the Company, on the one hand, and the Underwriters, on the other hand, in connection with the offering of the Offered Securities pursuant to this Agreement shall be deemed to be in the same respective proportions as the total proceeds from the offering of the Offered Securities pursuant to this Agreement (before deducting expenses) received by the Company, and the total underwriting discounts and commissions received by the Underwriters, in each case as set forth on the front cover page of the Prospectus, bear to the aggregate public offering price of the Offered Securities as set forth on such cover. The relative fault of the Company, on the one hand, and the Underwriters, on the other hand, shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company, on the one hand, or the Underwriters, on the other hand, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The amount paid or payable by a party as a result of the losses, claims, damages, liabilities and expenses referred to above shall be deemed to include, subject to the limitations set forth in Section 9(c), any legal or other fees or expenses reasonably incurred by such party in connection with investigating or defending any action or claim. The provisions set forth in Section 9(c) with respect to notice of commencement of any action shall apply if a claim for contribution is to be made under this Section 10; provided, however, that no additional notice shall be required with respect to any action for which notice has been given under Section 9(c) for purposes of indemnification.

The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 10 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to in this Section 10.

Notwithstanding the provisions of this Section 10, no Underwriter shall be required to contribute any amount in excess of the underwriting discounts and commissions received by such Underwriter in connection with the Offered Securities underwritten by it and distributed to the public. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be

entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute pursuant to this Section 10 are several, and not joint, in proportion to their respective underwriting commitments as set forth opposite their respective names on Schedule A. For purposes of this Section 10, each affiliate, director, officer, employee and agent of an Underwriter and each person, if any, who controls an Underwriter within the meaning of the Securities Act or the Exchange Act shall have the same rights to contribution as such Underwriter, and each director of the Company, each officer of the Company who signed the Registration Statement or the F-6 Registration Statement, and each person, if any, who controls the Company within the meaning of the Securities Act and the Exchange Act shall have the same rights to contribution as the Company.

Section 11. Default of One or More of the Several Underwriters. If, on the First Closing Date or any Option Closing Date any one or more of the several Underwriters shall fail or refuse to purchase Offered Securities that it or they have agreed to purchase hereunder on such date, and the aggregate number of Offered Securities which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase does not exceed 10% of the aggregate number of the Offered Securities to be purchased on such date, the Representatives may make arrangements satisfactory to the Company for the purchase of such Offered Securities by other persons, including any of the Underwriters, but if no such arrangements are made by such date, the other Underwriters shall be obligated, severally and not jointly, in the proportions that the number of Firm Securities set forth opposite their respective names on Schedule A bears to the aggregate number of Firm Securities set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as may be specified by the Representatives with the consent of the non-defaulting Underwriters, to purchase the Offered Securities which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date. If, on the First Closing Date or any Option Closing Date any one or more of the Underwriters shall fail or refuse to purchase Offered Securities and the aggregate number of Offered Securities with respect to which such default occurs exceeds 10% of the aggregate number of Offered Securities to be purchased on such date, and arrangements satisfactory to the Representatives and the Company for the purchase of such Offered Securities are not made within 48 hours after such default, this Agreement shall terminate without liability of any party to any other party except that the provisions of Section 4, Section 7, Section 9 and Section 10 shall at all times be effective and shall survive such termination. In any such case either the Representatives or the Company shall have the right to postpone the First Closing Date or the applicable Option Closing Date, as the case may be, but in no event for longer than seven days in order that the required changes, if any, to the Registration Statement and the Prospectus or any other documents or arrangements may be effected.

As used in this Agreement, the term “Underwriter” shall be deemed to include any person substituted for a defaulting Underwriter under this Section 11. Any action taken under this Section 11 shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

Section 12. Termination of this Agreement. Prior to the purchase of the Firm Securities by the Underwriters on the First Closing Date, this Agreement may be terminated by Jefferies and Stifel by notice given to the Company if at any time: (i) trading or quotation in any of the Company’s securities shall have been suspended or limited by the Commission, the NASDAQ or AIM, or trading in securities generally on any of the NASDAQ, the New York Stock Exchange, the London Stock Exchange or AIM shall have been suspended or limited, or minimum or maximum prices shall have been generally established on any of such stock exchanges; (ii) a general banking moratorium shall have been declared by any of federal, New York or United Kingdom authorities; (iii) there shall have occurred any outbreak or escalation of national or international hostilities or any crisis or calamity, or any change in the United States, United Kingdom or international financial markets, or any substantial change or development involving a prospective substantial change in United States, United Kingdom or international political,

financial or economic conditions, as in the judgment of Jefferies and Stifel is material and adverse and makes it impracticable to market the Offered Securities in the manner and on the terms described in the Time of Sale Prospectus or the Prospectus or to enforce contracts for the sale of securities; (iv) in the judgment of Jefferies and Stifel there shall have occurred any Material Adverse Change; or (v) the Company shall have sustained a loss by strike, fire, flood, earthquake, accident or other calamity of such character as in the judgment of Jefferies and Stifel may interfere materially with the conduct of the business and operations of the Company regardless of whether or not such loss shall have been insured. Any termination pursuant to this Section 12 shall be without liability on the part of (a) the Company to any Underwriter, except that the Company shall be obligated to reimburse the expenses of the Representatives and the Underwriters pursuant to Section 4 or Section 7 hereof or (b) any Underwriter to the Company; provided, however, that the provisions of Section 9 and Section 10 shall at all times be effective and shall survive such termination.

Section 13. No Advisory or Fiduciary Relationship. The Company acknowledges and agrees that (a) the purchase and sale of the Offered Securities pursuant to this Agreement, including the determination of the public offering price of the Offered Securities and any related discounts and commissions, is an arm’s-length commercial transaction between the Company, on the one hand, and the several Underwriters, on the other hand, (b) in connection with the offering contemplated hereby and the process leading to such transaction, each Underwriter is and has been acting solely as a principal and is not the agent or fiduciary of the Company, or its stockholders, creditors, employees or any other party, (c) no Underwriter has assumed or will assume an advisory or fiduciary responsibility in favor of the Company with respect to the offering contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company on other matters) and no Underwriter has any obligation to the Company with respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement, (d) the Underwriters and their respective affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Company, and (e) the Underwriters have not provided any legal, accounting, regulatory or tax advice with respect to the offering contemplated hereby and the Company has consulted its own legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

Section 14. Representations and Indemnities to Survive Delivery. The respective indemnities, agreements, representations, warranties and other statements of the Company, of its officers and of the several Underwriters set forth in or made pursuant to this Agreement will remain in full force and effect, regardless of any investigation made by or on behalf of any Underwriter or the Company or any of its or their partners, officers or directors or any controlling person, as the case may be, and, anything herein to the contrary notwithstanding, will survive delivery of and payment for the Offered Securities sold hereunder and any termination of this Agreement.

Section 15. Notices. All communications hereunder shall be in writing and shall be mailed, hand delivered or telecopied and confirmed to the parties hereto as follows:

If to the Representatives:	Jefferies LLC
	520 Madison Avenue
	New York, New York 10022
	Facsimile: (646) 619-4437
	Attention: General Counsel

	Stifel, Nicolaus & Company, Incorporated
	787 Seventh Avenue, 11th Floor
	New York, New York 10019
	Attention: General Counsel

with a copy to:	Cooley LLP
	1114 Avenue of the Americas
	New York, NY 10036-7798
	Attention: Divakar Gupta

If to the Company:	Verona Pharma plc
	3 More London Riverside
	London SE1 2RE UK
	Attention: Jan-Anders Karlsson, Chief Executive Officer

with a copy to:	Latham & Watkins LLP
	200 Clarendon Street
	Boston, Massachusetts 02116
	Attention: Peter N. Handrinos

Any party hereto may change the address for receipt of communications by giving written notice to the others.

Section 16. Successors. This Agreement will inure to the benefit of and be binding upon the parties hereto, including any substitute Underwriters pursuant to Section 11 hereof, and to the benefit of the affiliates, directors, officers, employees, agents and controlling persons referred to in Section 9 and Section 10, and in each case their respective successors, and no other person will have any right or obligation hereunder. The term “successors” shall not include any purchaser of the Offered Securities as such from any of the Underwriters merely by reason of such purchase.

Section 17. Partial Unenforceability. The invalidity or unenforceability of any section, paragraph or provision of this Agreement shall not affect the validity or enforceability of any other section, paragraph or provision hereof. If any section, paragraph or provision of this Agreement is for any reason determined to be invalid or unenforceable, there shall be deemed to be made such minor changes (and only such minor changes) as are necessary to make it valid and enforceable.

Section 18. Governing Law Provisions; Currency Provisions. This Agreement shall be governed by and construed in accordance with the internal laws of the State of New York applicable to agreements made and to be performed in such state. Any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby (“Related Proceedings”) may be instituted in the federal courts of the United States of America located in the Borough of Manhattan in the City of New York or the courts of the State of New York in each case located in the Borough of Manhattan in the City of New York (collectively, the “Specified Courts”), and each party irrevocably submits to the exclusive jurisdiction (except for proceedings instituted in regard to the enforcement of a judgment of any such court (a “Related Judgment”), as to which such jurisdiction is non-exclusive) of such courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail to such party’s address set forth above shall be effective service of process for any suit, action or other proceeding brought in any such court. The parties irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead or claim in any such court that any such suit, action or other proceeding brought in any such court has been brought in an inconvenient forum. The Company has irrevocably appointed CT Corporation System, which currently maintains a New York City office at 10 East 40 Street, 10th Floor, New York, N.Y. 10016, United States of America, as its agent to receive service of process or other legal summons for purposes of any such suit, action or proceeding that may be instituted in any state or federal court in the Borough of Manhattan in the City of New York, United States of America.

With respect to any Related Proceeding, each party irrevocably waives, to the fullest extent permitted by applicable law, all immunity (whether on the basis of sovereignty or otherwise) from jurisdiction, service of process, attachment (both before and after judgment) and execution to which it might otherwise be entitled in the Specified Courts, and with respect to any Related Judgment, each party waives any such immunity in the Specified Courts or any other court of competent jurisdiction, and will not raise or claim or cause to be pleaded any such immunity at or in respect of any such Related Proceeding or Related Judgment, including, without limitation, any immunity pursuant to the United States Foreign Sovereign Immunities Act of 1976, as amended.

The obligations of the Company pursuant to this Agreement in respect of any sum due to any Underwriter shall, notwithstanding any judgment in a currency other than United States dollars, not be discharged until the first business day, following receipt by any Underwriter of any sum adjudged to be so due in such other currency, on which such Underwriter may in accordance with normal banking procedures purchase United States dollars with such other currency. If the United States dollars so purchased are less than the sum originally due to such Underwriter in United States dollars hereunder, the Company agrees as a separate obligation and notwithstanding any such judgment, to indemnify such Underwriter against such loss. If the United States dollars so purchased are greater than the sum originally due to such Underwriter hereunder, such Underwriter agrees to pay to the Company an amount equal to the excess of the dollars so purchased over the sum originally due to such Underwriter hereunder.

All payments made by the Company under this Agreement, if any, will be made without withholding or deduction for or on account of any present or future taxes, duties, assessments or governmental charges of whatever nature (other than taxes on net income) imposed or levied by or on behalf of the United Kingdom or any political subdivision or any taxing authority thereof or therein unless the Company is or becomes required by law to withhold or deduct such taxes, duties, assessments or other governmental charges. In such event, the Company will pay such additional amounts as will result, after such withholding or deduction, in the receipt by each Underwriter and each person controlling any Underwriter, as the case may be, of the amounts that would otherwise have been receivable in respect thereof.

Section 19. General Provisions. This Agreement constitutes the entire agreement of the parties to this Agreement and supersedes all prior written or oral and all contemporaneous oral agreements, understandings and negotiations with respect to the subject matter hereof. This Agreement may be executed in two or more counterparts, each one of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. This Agreement may not be amended or modified unless in writing by all of the parties hereto, and no condition herein (express or implied) may be waived unless waived in writing by each party whom the condition is meant to benefit. The section headings herein are for the convenience of the parties only and shall not affect the construction or interpretation of this Agreement.

Each of the parties hereto acknowledges that it is a sophisticated business person who was adequately represented by counsel during negotiations regarding the provisions hereof, including, without limitation, the indemnification provisions of Section 9 and the contribution provisions of Section 10, and is fully informed regarding said provisions. Each of the parties hereto further acknowledges that the provisions of Section 9 and Section 10 hereof fairly allocate the risks in light of the ability of the parties to investigate the Company, its affairs and its business in order to assure that adequate disclosure has been made in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, each free writing prospectus and the Prospectus (and any amendments and supplements to the foregoing), as contemplated by the Securities Act and the Exchange Act.

If the foregoing is in accordance with your understanding of our agreement, kindly sign and return to the Company the enclosed copies hereof, whereupon this instrument, along with all counterparts hereof, shall become a binding agreement in accordance with its terms.

	Very truly yours,

	Verona Pharma plc


	By:
		Name:
		Title:

The foregoing Underwriting Agreement is hereby confirmed and accepted by the Representatives in New York, New York as of the date first above written.

JEFFERIES LLC
STIFEL, NICOLAUS & COMPANY, INCORPORATED
Acting individually and as Representatives of the several Underwriters named in the attached Schedule A.


JEFFERIES LLC


By:
	Name:
	Title:

STIFEL, NICOLAUS & COMPANY, INCORPORATED


By:
	Name:
	Title:

Schedule A

Underwriters	Number of Firm Securities to be Purchased
	ADSs	Ordinary Shares
Jefferies LLC	[·]	[·]
Stifel, Nicolaus & Company, Incorporated	[·]	[·]
Wedbush Securities, Inc.	[·]	[·]
SunTrust Robinson Humphrey Inc.	[·]	[·]
Total	[·]	[·]

Schedule C

Pricing Information

Price to Public:	$[·] per ADS

	£[·] per Ordinary Share

Firm Securities:	[·] ADSs, representing [·] Ordinary Shares

	[·] Ordinary Shares

Optional Securities:	[·] ADSs, representing [·] Ordinary Shares

	[·] Ordinary Shares

Exhibit A

Form of Lock-up Agreement

, 201

Jefferies International Limited
Stifel, Nicolaus & Company, Incorporated

As Representatives of the Several Underwriters

c/o Jefferies International Limited
Vintners Place

68 Upper Thames Street

London EC4V 3BJ

United Kingdom

and

c/o Stifel, Nicolaus & Company, Incorporated

787 Seventh Avenue, 11th Floor

New York, New York 10019

RE: Verona Pharma plc (the “Company”)

Ladies & Gentlemen:

The undersigned is an officer or director of the Company and/or an owner of ordinary shares, nominal value £0.01 per share, of the Company (“Ordinary Shares”), or of securities convertible into or exchangeable or exercisable for Ordinary Shares. The Company proposes to conduct a public offering of American Depositary Shares (“ADSs”) of the Company representing Ordinary Shares (the “Offering”), for which Jefferies International Limited (“Jefferies”) and Stifel, Nicolaus & Company, Incorporated (“Stifel”) will act as the representatives of the underwriters. The undersigned recognizes that the Offering will benefit each of the Company and the undersigned. The undersigned acknowledges that the underwriters are relying on the representations and agreements of the undersigned contained in this letter agreement in conducting the Offering and, at a subsequent date, in entering into an underwriting agreement (the “Underwriting Agreement”) and other underwriting arrangements with the Company with respect to the Offering.

Annex A sets forth definitions for capitalized terms used in this letter agreement that are not defined in the body of this letter agreement. Those definitions are a part of this letter agreement.

In consideration of the foregoing, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees that, during the Lock-up Period, the undersigned will not (and will cause any Family Member not to), without the prior written consent of Jefferies and Stifel, which may withhold their consent in their sole discretion:

· Sell or Offer to Sell any Ordinary Shares or Related Securities currently or hereafter owned either of record or beneficially (as defined in Rule 13d-3 under the Exchange Act) by the undersigned or such Family Member,

· enter into any Swap,

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· make any demand for, or exercise any right with respect to, the registration under the Securities Act of the offer and sale of any Ordinary Shares or Related Securities, or cause to be filed a registration statement, prospectus or prospectus supplement (or an amendment or supplement thereto) with respect to any such registration, or

· publicly announce any intention to do any of the foregoing.

The foregoing will not apply to (i) the registration of the offer and sale of the ADSs and the sale of such ADSs to the underwriters, in each case, as contemplated by the Underwriting Agreement or (ii) the deposit of Ordinary Shares with the Depositary, in exchange for the issuance of ADSs, or the cancellation of ADSs in exchange for the issuance of Ordinary Shares, provided that such ADSs or Ordinary Shares issued pursuant to this clause (ii) held by the undersigned shall remain subject to the terms of this letter agreement. In addition, the foregoing restrictions shall not apply to:

(i) the transfer of Ordinary Shares or Related Securities by gift, or by will or intestate succession to a Family Member or to a trust whose beneficiaries consist exclusively of one or more of the undersigned and/or a Family Member;

(ii) (x) transfers or dispositions of Ordinary Shares or Related Securities to any corporation, partnership, limited liability company or other legal entity, all of the beneficial ownership interests of which are held by the undersigned or any Family Member or that controls or is controlled by, or is under common control with, the undersigned, or (y) in the case of an investment fund, that is managed by, or is under common management with, the undersigned (including, for the avoidance of doubt, a fund managed by the same manager or managing member or general partner or management company or by an entity controlling, controlled by, or under common control with such manager or managing member or general partner or management company as the undersigned or who shares a common investment advisor with the undersigned), distributions of Ordinary Shares or Related Securities to limited partners, members, stockholders or other equityholders of the undersigned, provided that, in each case, any such transfer or distribution shall not involve a disposition for value; and

(iii) the transfer of Ordinary Shares or Related Securities by operation of law, including pursuant to a domestic order or negotiated divorce settlement;

provided, however, that in any such transfer or distribution, it shall be a condition to such transfer that:

· each donee, transferee or distributee executes and delivers to Jefferies and Stifel an agreement in form and substance satisfactory to Jefferies and Stifel stating that such donee, transferee or distributee is receiving and holding such Ordinary Shares and/or Related Securities subject to the provisions of this letter agreement and agrees not to Sell or Offer to Sell such Ordinary Shares and/or Related Securities, engage in any Swap or engage in any other activities restricted under this letter agreement except in accordance with this letter agreement (as if such donee, transferee or distributee had been an original signatory hereto), and

· prior to the expiration of the Lock-up Period, no public disclosure or filing, including under the Exchange Act or applicable rules and regulations of AIM, by any party to the transfer (donor, donee, transferor or transferee, distributor or distributee) shall be required, or made voluntarily, in connection with such transfer or distribution.

Furthermore, notwithstanding the restrictions imposed by this letter agreement, the undersigned may:

(i) exercise an option or other equity award to purchase Ordinary Shares or ADSs, as applicable,

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granted under any of the Company’s equity incentive plans or equity purchase plans existing as of the date hereof and described in the Prospectus (as defined in the Underwriting Agreement), whether for cash or by net exercise or “cashless” exercise, insofar as such option or other equity award is outstanding as of the date of the Prospectus, provided that the underlying Ordinary Shares or ADSs, as applicable, shall continue to be subject to the restrictions on transfer set forth in this letter agreement and provided further that, if required, any public report or filing, including under the Exchange Act or applicable rules and regulations of AIM, shall clearly indicate in the footnotes thereto that the filing relates to the exercise of an option, that no Ordinary Shares or ADSs, as applicable, were sold by the reporting person and that Ordinary Shares or ADSs, as applicable, received upon exercise of the option are subject to this letter agreement;

(ii) exercise a warrant to purchase Ordinary Shares or ADSs, as applicable, existing as of the date hereof and described in the Prospectus, whether for cash or by net exercise or “cashless” exercise, provided that the underlying Ordinary Shares or ADSs, as applicable, shall continue to be subject to the restrictions on transfer set forth in this letter agreement and provided further that, if required, any public report or filing, including under the Exchange Act or applicable rules and regulations of AIM, shall clearly indicate in the footnotes thereto that the filing relates to the exercise of a warrant, that no Ordinary Shares or ADSs, as applicable, were sold by the reporting person and that Ordinary Shares or ADSs, as applicable, received upon exercise of the warrant are subject to this letter agreement;

(iii) establish a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of Ordinary Shares or ADSs, provided that, such plan does not provide for any transfers of Ordinary Shares or Related Securities during the Lock-up Period and the entry into such plan is not publicly disclosed, including in any filings under the Exchange Act or applicable rules and regulations of AIM, during the Lock-up Period;

(iv) transfer or dispose of ADSs acquired in the Offering (other than any Company-directed ADSs purchased in the Offering by an officer or director of the Company) or Ordinary Shares or ADSs acquired on the open market following the Offering, provided that, in each case, no public report or filing, including under the Exchange Act or applicable rules and regulations of AIM, shall be required, or made voluntarily, in connection with such transfer or disposition during the Lock-Up Period;

(v) transfer Ordinary Shares or ADSs to the Company as forfeitures to satisfy tax withholding obligations of the undersigned in connection with the vesting or exercise of equity awards by the undersigned pursuant to the Company’s equity incentive plans existing as of the date hereof and described in the Prospectus, insofar as such equity awards are outstanding as of the date of the Prospectus, provided that, if required, any public report or filing, including under the Exchange Act or applicable rules and regulations of AIM, shall clearly indicate in the footnotes thereto that the purpose of such transfer was to cover tax obligations of the undersigned in connection with such vesting or exercise; or

(vi) pursuant to a bona fide third-party tender offer for all outstanding shares of the Company, merger, consolidation or other similar transaction made to all holders of the Company’s securities involving a change of control of the Company (including, without limitation, the entering into any lock-up, voting or similar agreement pursuant to which the undersigned may agree to transfer, sell, tender or otherwise dispose of Ordinary Shares, ADSs, or other such securities in connection with such transaction, or vote any Ordinary Shares, ADSs, or other such securities in favor of any such transaction), provided that, in the event that such tender offer, merger, consolidation or other such transaction is not completed, such securities held by the undersigned shall remain subject to

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the provisions of this letter agreement.

If the undersigned is an officer or director of the Company, the undersigned further agrees that the foregoing provisions shall be equally applicable to any Company-directed ADSs the undersigned may purchase or otherwise receive in the Offering (including pursuant to a directed share program).

In addition, if the undersigned is an officer or director of the Company, (i) Jefferies and Stifel agree that, at least three business days before the effective date of any release or waiver of the foregoing restrictions in connection with a transfer of Ordinary Shares and/or Related Securities, Jefferies and Stifel will notify the Company of the impending release or waiver, and (ii) the Company (in accordance with the provisions of the Underwriting Agreement) will announce the impending release or waiver by press release through a major news service at least two business days before the effective date of the release or waiver. Any release or waiver granted by Jefferies and Stifel hereunder to any such officer or director shall only be effective two business days after the publication date of such press release. The provisions of this paragraph will not apply if both (a) the release or waiver is effected solely to permit a transfer not for consideration and (b) the transferee has agreed in writing to be bound by the same terms described in this letter agreement that are applicable to the transferor to the extent and for the duration that such terms remain in effect at the time of the transfer.

The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of Ordinary Shares and/or Related Securities held by the undersigned and the undersigned’s Family Members, if any, except in compliance with the foregoing restrictions.

With respect to the Offering only, the undersigned waives any registration rights relating to registration under the Securities Act of the offer and sale of any Ordinary Shares and/or any Related Securities owned either of record or beneficially by the undersigned, including any rights to receive notice of the Offering.

The undersigned confirms that the undersigned has not, and has no knowledge that any Family Member has, directly or indirectly, taken any action designed to or that might reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale of the ADSs. The undersigned will not, and will cause any Family Member not to take, directly or indirectly, any such action.

Whether or not the Offering occurs as currently contemplated or at all depends on market conditions and other factors. The Offering will only be made pursuant to the Underwriting Agreement, the terms of which are subject to negotiation between the Company and the underwriters.

If (i) the Company, on the one hand, or Jefferies and Stifel, on the other hand, notifies the other in writing that it does not intend to proceed with the Offering, (ii) the Company files an application to withdraw the registration statement related to the Offering, (iii) the Underwriting Agreement is not executed on or before June 30, 2017, or (iv) the Underwriting Agreement (other than the provisions thereof that survive termination) terminates or is terminated prior to the Closing Date, then in each case, this letter agreement shall automatically, and without any action on the part of any other party, terminate and be of no further force and effect, and the undersigned shall automatically be released from the obligations under this letter agreement.

The undersigned hereby represents and warrants that the undersigned has full power, capacity and authority to enter into this letter agreement. This letter agreement is irrevocable and will be binding on the undersigned and the successors, heirs, personal representatives and assigns of the undersigned.

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Name of Entity (as applicable)


Signature


Printed Name of Person Signing

(Indicate capacity of person signing if signing as custodian or trustee, or on behalf of an entity)

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Certain Defined Terms
Used in Lock-up Agreement

For purposes of the letter agreement to which this Annex A is attached and of which it is made a part:

· “AIM” shall mean AIM, a market operated by the London Stock Exchange plc.

· “Call Equivalent Position” shall have the meaning set forth in Rule 16a-1(b) under the Exchange Act.

· “Exchange Act” shall mean the Securities Exchange Act of 1934, as amended.

· “Family Member” shall mean the spouse of the undersigned, an immediate family member of the undersigned or an immediate family member of the undersigned’s spouse, in each case living in the undersigned’s household or whose principal residence is the undersigned’s household (regardless of whether such spouse or family member may at the time be living elsewhere due to educational activities, health care treatment, military service, temporary internship or employment or otherwise). “Immediate family member” as used above shall have the meaning set forth in Rule 16a-1(e) under the Exchange Act.

· “Lock-up Period” shall mean the period beginning on the date hereof and continuing through the close of trading on the date that is 180 days after the date of the Prospectus (as defined in the Underwriting Agreement).

· “Put Equivalent Position” shall have the meaning set forth in Rule 16a-1(h) under the Exchange Act.

· “Related Securities” shall mean any ADSs or options or warrants or other rights to acquire ADSs or Ordinary Shares or any securities exchangeable or exercisable for or convertible into ADSs or Ordinary Shares, or to acquire other securities or rights ultimately exchangeable or exercisable for or convertible into ADSs or Ordinary Shares.

· “Securities Act” shall mean the Securities Act of 1933, as amended.

· “Sell or Offer to Sell” shall mean to:

1. – sell, offer to sell, contract to sell or lend,

2. – effect any short sale or establish or increase a Put Equivalent Position or liquidate or decrease any Call Equivalent Position

3. – pledge, hypothecate or grant any security interest in, or

4. – in any other way transfer or dispose of,

in each case whether effected directly or indirectly.

· “Swap” shall mean any swap, hedge or similar arrangement or agreement that transfers, in whole or in part, the economic risk of ownership of Ordinary Shares or Related Securities, regardless of whether any such transaction is to be settled in securities, in cash or otherwise.

Capitalized terms not defined in this Annex A shall have the meanings given to them in the body of this lock-up agreement.

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Exhibit B

Directors, Officers and Others
Signing Lock-up Agreement

Directors:

David Ebsworth

Ken Cunningham

Patrick Humphrey

Rishi Gupta

Mahendra G. Shah

Andrew Sinclair

Vikas Sinha

Anders Ullman

Officers:

Jan-Anders Karlsson

Piers Morgan

Claire Poll

Kenneth Newman

Peter Spargo

Richard Hennings

Others:

Vivo Ventures Fund VII, L.P.

Vivo Ventures Fund VII Affiliates Fund, L.P.

Vivo Ventures Fund VI, L.P.

Vivo Ventures VI Affiliates Fund, L.P.

Arthurian Life Sciences SPV Limited, as general partner of the Wales Life Sciences Investment Fund LP

Arix Bioscience PLC

OrbiMed Private Investments VI, LP

Growth Equity Opportunities Fund IV, LLC

Abingworth Bioventures VI LP

Tekla Life Sciences Investors

Tekla World Healthcare Fund

Aisling Capital IV, LP

Novo A/S

Biodiscovery 4 PFCI

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